wxGUI: escape ampersand when writing d.wms into workspace, see https://trac.osgeo.org/grass/ticket/3147 (merge from trunk, https://trac.osgeo.org/grass/changeset/69445)

git-svn-id: https://svn.osgeo.org/grass/grass/branches/releasebranch_7_0@69447 15284696-431f-4ddb-bdfa-cd5b030d7da7

gui/wxpython/core/workspace.py

@@ -72,6 +72,7 @@ class ProcessWorkspaceFile:
         """
         value = value.replace('&lt;', '<')
         value = value.replace('&gt;', '>')
+        value = value.replace('&', '&amp;')
         
         return value