Fix install path libmpdclient.pc (from datadir -> libdir)
Fix install path libmpdclient.pc (from datadir -> libdir)

sl0th/libmpdclient,jagleeso/libmpdclient,jagleeso/libmpdclient,jagleeso/libmpdclient,yusiwen/libmpdclient,sl0th/libmpdclient,jwise/libmpdclient,yusiwen/libmpdclient,jwise/libmpdclient,psych0tik/libmpdclient2,OpenInkpot-archive/iplinux-libmpdclient,cmende/libmpdclient,sl0th/libmpdclient,jwise/libmpdclient,cmende/libmpdclient,psych0tik/libmpdclient2,yusiwen/libmpdclient,cmende/libmpdclient,OpenInkpot-archive/iplinux-libmpdclient