plugin text_syntaxes: rstrip the conversion result to avoid new lines systematically added by converters (e.g. html2text do this)

src/plugins/plugin_misc_text_syntaxes.py

@@ -216,6 +216,8 @@ class TextSyntaxes(object):
         else:
             d.addCallback(lambda xhtml: deferToThread(syntaxes[syntax_to]["from"], xhtml))
 
+        # converters can add new lines that disturb the microblog change detection
+        d.addCallback(lambda text: text.rstrip())
         return d
 
     def addSyntax(self, name, to_xhtml_cb, from_xhtml_cb, flags = None):