[pre-commit.ci] auto fixes from pre-commit hooks

Author: pre-commit-ci[bot]

Diff for: src/diffpy/pdfgui/gui/mainframe.py

@@ -2522,7 +2522,7 @@ def onSaveCalc(self, event):
     def onDocumentation(self, event):
         """Show information about the documentation."""
         import webbrowser
-        
+
         webbrowser.open(docMainFile)
         return