astconfigparser: Handle case where line is simply a comment.

Change-Id: I2dea5815363f4d787d709228a04f33baee383ef5

contrib/scripts/sip_to_pjsip/astconfigparser.py

@@ -203,6 +203,9 @@ def remove_comment(line, is_comment):
     if match:
          # the end of where the real string is is where the comment starts
          line = line[0:(match.end()-1)]
+    elif line.startswith(";"):
+         # if the line is actually a comment just ignore it all
+         line = ""
 
     return line.replace("\\", "").strip(), False