Fix DelegateType.copy
Fix DelegateType.copy

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