Print error message when proxy URL format is incorrect
Print error message when proxy URL format is incorrect

twahlfeld/pianobar,gnowxilef/pianobar,bmbove/pianobar-save,johnso51/pianobar,tchajed/pianobar,DavidZemon/pianobar,twahlfeld/pianobar,gnowxilef/pianobar,johndeeney/pianobar,gnowxilef/pianobar,johndeeney/pianobar,bmbove/pianobar-save,DavidZemon/pianobar,bmbove/pianobar-save,twahlfeld/pianobar,bmbove/pianobar-save,bmbove/pianobar-save,gnowxilef/pianobar,twahlfeld/pianobar,johndeeney/pianobar,johnso51/pianobar,twahlfeld/pianobar,gnowxilef/pianobar,gnowxilef/pianobar,johnso51/pianobar,johndeeney/pianobar,DavidZemon/pianobar,tchajed/pianobar,tchajed/pianobar,twahlfeld/pianobar,tchajed/pianobar,johnso51/pianobar,tchajed/pianobar,johndeeney/pianobar,DavidZemon/pianobar,DavidZemon/pianobar,johnso51/pianobar,tchajed/pianobar,johndeeney/pianobar,johnso51/pianobar,DavidZemon/pianobar