fix: set maxium progressbar to 1

This solves matze#274.

src/beamerouterthememoloch.dtx

@@ -191,9 +191,7 @@
 \setlength{\moloch@progressinheadfoot@linewidth}{0.4pt}
 \setbeamertemplate{progress bar in head/foot}{
   \nointerlineskip
-  \setlength{\moloch@progressinheadfoot}{%
-    \paperwidth * \ratio{\insertframenumber pt}{\inserttotalframenumber pt}%
-  }%
+  \pgfmathsetlength{\metropolis@progressinheadfoot}{\paperwidth * min(1,\insertframenumber/\inserttotalframenumber}
   \begin{beamercolorbox}[wd=\paperwidth]{progress bar in head/foot}
     \tikzexternaldisable%
     \begin{tikzpicture}