girparser: accept empty tuple for parameters without initializer
girparser: accept empty tuple for parameters without initializer

frida/vala,flobrosch/vala-fixes,spidermonkdust/vala,frida/vala,flobrosch/vala-fixes,frida/vala,Distrotech/vala,frida/vala,GNOME/vala,rvu95/vala,GNOME/vala,spidermonkdust/vala,Distrotech/vala,rvu95/vala,flobrosch/vala-fixes,rvu95/vala,GNOME/vala,GNOME/vala,spidermonkdust/vala,frida/vala,xdave/pvala,Distrotech/vala