build: Fix parallel install failure
build: Fix parallel install failure

libgoa-backend-1.0 must be installed before libgoawebextension;
unpleasant automake syntax required.

https://bugzilla.gnome.org/show_bug.cgi?id=750897

ritzk/gnome-online-accounts,felipeborges/gnome-online-accounts,ritzk/gnome-online-accounts,felipeborges/gnome-online-accounts,ritzk/gnome-online-accounts,felipeborges/gnome-online-accounts