GIR parser: Fix construct-only attribute parsing for properties
GIR parser: Fix construct-only attribute parsing for properties

Signed-off-by: Didier 'Ptitjes <9b75d9bd0301369bd978ce18252ab1844af4cc4b@free.fr>

lovebug356/vala,kamanashisroy/aroop,severinh/vala,GNOME/vala,Jc2k/vala,rvu95/vala,playya/vala,playya/vala,tjol/vala-tjol,GNOME/vala,rvu95/vala,playya/vala,severinh/vala,Distrotech/vala,flobrosch/vala-fixes,xdave/pvala,lovebug356/vala,spidermonkdust/vala,jessevdk/vala,frida/vala,jessevdk/vala,themiwi/vala,Distrotech/vala,themiwi/vala,kamanashisroy/aroop,frida/vala,Distrotech/vala,themiwi/vala,kamanashisroy/aroop,GNOME/vala,spidermonkdust/vala,phako/vala,tjol/vala-tjol,frida/vala,tjol/vala-tjol,spidermonkdust/vala,flobrosch/vala-fixes,phako/vala,severinh/vala,frida/vala,Jc2k/vala,frida/vala,rvu95/vala,GNOME/vala,jessevdk/vala,flobrosch/vala-fixes