Allow NULL to be stored into GSettings trees
Allow NULL to be stored into GSettings trees

This is used for resets (in theory) and currently it crashes when
freeing the tree.

bluez-android/glib,iConsole/Console-OS_external_bluetooth_glib,iConsole/Console-OS_external_bluetooth_glib,johne53/MB3Glib,MathieuDuponchelle/glib,cention-sany/glib,MathieuDuponchelle/glib,endlessm/glib,antono/glib,01org/android-bluez-glib,zsx/glib,darren-clark/android_platform_external_bluetooth_glib,krichter722/glib,zsx/glib,ieei/glib,MathieuDuponchelle/glib,tamaskenez/glib,djdeath/glib,gale320/glib,antono/glib,krichter722/glib,ieei/glib,zsx/glib,justinkb/aosp-bluez.glib,krichter722/glib,gale320/glib,djdeath/glib,cosimoc/glib,mzabaluev/glib,bluez-android/glib,MathieuDuponchelle/glib,darren-clark/android_platform_external_bluetooth_glib,pstglia/external-bluetooth-glib,Distrotech/glib,cosimoc/glib,tamaskenez/glib,bluez-android/glib,gale320/glib,gale320/glib,justinkb/aosp-bluez.glib,cosimoc/glib,pstglia/platform-external-bluetooth-glib,cosimoc/glib,zsx/glib,Distrotech/glib,tamaskenez/glib,endlessm/glib,tchakabam/glib,mzabaluev/glib,pstglia/external-bluetooth-glib,01org/android-bluez-glib,justinkb/aosp-bluez.glib,lukasz-skalski/glib,krichter722/glib,johne53/MB3Glib,lukasz-skalski/glib,iConsole/Console-OS_external_bluetooth_glib,lukasz-skalski/glib,darren-clark/android_platform_external_bluetooth_glib,antono/glib,mzabaluev/glib,pstglia/external-bluetooth-glib,antono/glib,mzabaluev/glib,djdeath/glib,cention-sany/glib,ieei/glib,djdeath/glib,lukasz-skalski/glib,tchakabam/glib,cention-sany/glib,cosimoc/glib,johne53/MB3Glib,pstglia/external-bluetooth-glib,djdeath/glib,tchakabam/glib,tamaskenez/glib,mzabaluev/glib,ieei/glib,darren-clark/android_platform_external_bluetooth_glib,cention-sany/glib,bluez-android/glib,justinkb/aosp-bluez.glib,pstglia/platform-external-bluetooth-glib,iConsole/Console-OS_external_bluetooth_glib,darren-clark/android_platform_external_bluetooth_glib,MathieuDuponchelle/glib,bluez-android/glib,Distrotech/glib,krichter722/glib,johne53/MB3Glib,pstglia/platform-external-bluetooth-glib,gale320/glib,01org/android-bluez-glib,endlessm/glib,justinkb/aosp-bluez.glib,Distrotech/glib,pstglia/external-bluetooth-glib,endlessm/glib,cention-sany/glib,tchakabam/glib,Distrotech/glib,pstglia/platform-external-bluetooth-glib,tchakabam/glib,johne53/MB3Glib,lukasz-skalski/glib,johne53/MB3Glib,01org/android-bluez-glib,iConsole/Console-OS_external_bluetooth_glib,endlessm/glib,pstglia/platform-external-bluetooth-glib,01org/android-bluez-glib,tamaskenez/glib,ieei/glib