[notify] remove some useless forward declarations
[notify] remove some useless forward declarations

These cause trouble in the next commit.

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