gconf.bbclass: Sync with Poky
gconf.bbclass: Sync with Poky

* Only add the postinstall script header if an existing postinstall isn't set
* Remove the unneeded python import
* Fix the indentation in the postinstall function

Signed-off-by: Richard Purdie <a03894c799ea916bd571ce8f12ed88f6fb3400f7@linux.intel.com>

Martix/Eonos,sledz/oe,openembedded/openembedded,sutajiokousagi/openembedded,yyli/overo-oe,BlackPole/bp-openembedded,sutajiokousagi/openembedded,nx111/openembeded_openpli2.1_nx111,mrchapp/arago-oe-dev,rascalmicro/openembedded-rascal,John-NY/overo-oe,dellysunnymtech/sakoman-oe,SIFTeam/openembedded,sampov2/audio-openembedded,JamesAng/oe,crystalfontz/openembedded,nx111/openembeded_openpli2.1_nx111,Martix/Eonos,bticino/openembedded,dave-billin/overo-ui-moos-auv,SIFTeam/openembedded,SIFTeam/openembedded,dave-billin/overo-ui-moos-auv,bticino/openembedded,sledz/oe,giobauermeister/openembedded,scottellis/overo-oe,openpli-arm/openembedded,openembedded/openembedded,libo/openembedded,rascalmicro/openembedded-rascal,BlackPole/bp-openembedded,BlackPole/bp-openembedded,openpli-arm/openembedded,openpli-arm/openembedded,anguslees/openembedded-android,BlackPole/bp-openembedded,yyli/overo-oe,openembedded/openembedded,crystalfontz/openembedded,openpli-arm/openembedded,scottellis/overo-oe,JamesAng/oe,rascalmicro/openembedded-rascal,hulifox008/openembedded,sledz/oe,sutajiokousagi/openembedded,SIFTeam/openembedded,nx111/openembeded_openpli2.1_nx111,mrchapp/arago-oe-dev,John-NY/overo-oe,hulifox008/openembedded,JamesAng/oe,Martix/Eonos,thebohemian/openembedded,JamesAng/oe,sutajiokousagi/openembedded,yyli/overo-oe,dellysunnymtech/sakoman-oe,hulifox008/openembedded,openpli-arm/openembedded,sledz/oe,trini/openembedded,trini/openembedded,sledz/oe,rascalmicro/openembedded-rascal,buglabs/oe-buglabs,John-NY/overo-oe,SIFTeam/openembedded,openembedded/openembedded,nx111/openembeded_openpli2.1_nx111,crystalfontz/openembedded,sampov2/audio-openembedded,libo/openembedded,mrchapp/arago-oe-dev,buglabs/oe-buglabs,buglabs/oe-buglabs,trini/openembedded,dellysunnymtech/sakoman-oe,libo/openembedded,libo/openembedded,thebohemian/openembedded,giobauermeister/openembedded,yyli/overo-oe,sentient-energy/emsw-oe-mirror,dellysunnymtech/sakoman-oe,openembedded/openembedded,sledz/oe,JamesAng/oe,sentient-energy/emsw-oe-mirror,yyli/overo-oe,crystalfontz/openembedded,dave-billin/overo-ui-moos-auv,anguslees/openembedded-android,anguslees/openembedded-android,libo/openembedded,nx111/openembeded_openpli2.1_nx111,xifengchuo/openembedded,crystalfontz/openembedded,dellysunnymtech/sakoman-oe,giobauermeister/openembedded,sutajiokousagi/openembedded,bticino/openembedded,buglabs/oe-buglabs,Martix/Eonos,xifengchuo/openembedded,thebohemian/openembedded,sampov2/audio-openembedded,rascalmicro/openembedded-rascal,mrchapp/arago-oe-dev,scottellis/overo-oe,nx111/openembeded_openpli2.1_nx111,yyli/overo-oe,SIFTeam/openembedded,hulifox008/openembedded,giobauermeister/openembedded,sentient-energy/emsw-oe-mirror,dave-billin/overo-ui-moos-auv,SIFTeam/openembedded,BlackPole/bp-openembedded,giobauermeister/openembedded,JamesAng/goe,hulifox008/openembedded,bticino/openembedded,giobauermeister/openembedded,dave-billin/overo-ui-moos-auv,JamesAng/goe,bticino/openembedded,anguslees/openembedded-android,rascalmicro/openembedded-rascal,BlackPole/bp-openembedded,xifengchuo/openembedded,openembedded/openembedded,crystalfontz/openembedded,xifengchuo/openembedded,xifengchuo/openembedded,dave-billin/overo-ui-moos-auv,buglabs/oe-buglabs,Martix/Eonos,xifengchuo/openembedded,dellysunnymtech/sakoman-oe,Martix/Eonos,scottellis/overo-oe,libo/openembedded,hulifox008/openembedded,sentient-energy/emsw-oe-mirror,John-NY/overo-oe,mrchapp/arago-oe-dev,dellysunnymtech/sakoman-oe,trini/openembedded,giobauermeister/openembedded,thebohemian/openembedded,John-NY/overo-oe,anguslees/openembedded-android,sampov2/audio-openembedded,sentient-energy/emsw-oe-mirror,xifengchuo/openembedded,Martix/Eonos,JamesAng/goe,sutajiokousagi/openembedded,nx111/openembeded_openpli2.1_nx111,John-NY/overo-oe,JamesAng/oe,openembedded/openembedded,JamesAng/goe,trini/openembedded,yyli/overo-oe,openembedded/openembedded,bticino/openembedded,openpli-arm/openembedded,buglabs/oe-buglabs,rascalmicro/openembedded-rascal,scottellis/overo-oe,anguslees/openembedded-android,sledz/oe,JamesAng/oe,dave-billin/overo-ui-moos-auv,BlackPole/bp-openembedded,openembedded/openembedded,thebohemian/openembedded,dellysunnymtech/sakoman-oe,crystalfontz/openembedded,sampov2/audio-openembedded,dellysunnymtech/sakoman-oe,trini/openembedded,anguslees/openembedded-android,sentient-energy/emsw-oe-mirror,xifengchuo/openembedded,thebohemian/openembedded,giobauermeister/openembedded,nx111/openembeded_openpli2.1_nx111,sutajiokousagi/openembedded,hulifox008/openembedded,buglabs/oe-buglabs,openembedded/openembedded,John-NY/overo-oe,yyli/overo-oe,scottellis/overo-oe,giobauermeister/openembedded,JamesAng/goe,JamesAng/goe,xifengchuo/openembedded,libo/openembedded,rascalmicro/openembedded-rascal,sampov2/audio-openembedded,trini/openembedded,mrchapp/arago-oe-dev,JamesAng/goe,bticino/openembedded,openpli-arm/openembedded,mrchapp/arago-oe-dev,sampov2/audio-openembedded,sentient-energy/emsw-oe-mirror,openembedded/openembedded,buglabs/oe-buglabs,scottellis/overo-oe,thebohemian/openembedded