Inserturl als Null hinzugefügt

.gitignore

@@ -1,4 +1,5 @@
 *.*~
+*.vim
 *.SET
 *.ods#
 *.aux

ahilbig-presentation.sty

@@ -797,11 +797,13 @@
     {\usebeamercolor[fg]{info in title}\lecturename} \hbox{\translate{vom}
       \insertdate}%
       \vfill
+			\ifthenelse{\equal{\inserturl}{null}}{}{%
       \begin{tiny}
        %\versionsinfo
 							Quellen: \url{\inserturl}
       \end{tiny}
       \vfill
+			}
       \ifcd\hbox{\translate{ von}
       {\usebeamercolor[fg]{info in title}\insertauthor}}\fi}\par
   \ifcd\else\vskip6em