Fix naming issue with abstract async methods
Fix naming issue with abstract async methods

Fixes bug 623943.

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