Conditional certificate creation

src/freedombone

@@ -8402,7 +8402,9 @@ function install_voip {
   fi
 
   # Make an ssl cert for the server
-  makecert mumble
+  if [ ! -f /etc/ssl/certs/mumble.crt ]; then
+      makecert mumble
+  fi
 
   # Check that the cert was created
   if [ ! -f /etc/ssl/certs/mumble.crt ]; then