Remove leftover definition from gactiongroup.h
Remove leftover definition from gactiongroup.h

GContextActionGroupInterface is not currently used anywhere.

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