plugin text syntaxes: fix EscapeHTML following massive snake_case renaming

sat/plugins/plugin_misc_text_syntaxes.py

@@ -217,7 +217,7 @@ class TextSyntaxes(object):
             # XXX: we disable raw HTML parsing by default, to avoid parsing error
             #      when the user is not aware of markdown and HTML
             class EscapeHTML(Extension):
-                def extend_markdown(self, md):
+                def extendMarkdown(self, md):
                     md.preprocessors.deregister('html_block')
                     md.inlinePatterns.deregister('html')