Merge pull request #3045 from blankenberg/value_to_display_text-fix

Fix for displaying parameters to the user, that have a False value.

lib/galaxy/tools/parameters/basic.py

@@ -151,7 +151,7 @@ def value_to_display_text( self, value, app ):
         Convert a value to a text representation suitable for displaying to
         the user
         """
-        if value:
+        if value is not None:
             return unicodify( value )
         return "Not available."