Fix export unicode comments

Current script make 1 character for each byte in comment line. So it`s cause double length and incorrect chars in international comments from IDA in Ghidra. This small patch fix it.

GhidraBuild/IDAPro/Python/7xx/python/idaxml.py

@@ -632,7 +632,7 @@ class XmlExporter(IdaXml):
         # tag_remove seems to be losing last character
         # work around is to add a space
         cmt_text = ida_lines.tag_remove(cmt + ' ')
-        self.write_text(cmt_text)
+        self.write_text(cmt_text.decode('utf-8'))
         self.end_element(COMMENT, False)