Avoid NULL bytes when writing to file

lib/core/agent.py

@@ -746,6 +746,10 @@ class Agent(object):
         if intoRegExp:
             intoRegExp = intoRegExp.group(1)
             query = query[:query.index(intoRegExp)]
+            # The position is irrelevant when writing into a file,
+            # so bump the payload to the first position to avoid
+            # NULL bytes written into the file
+            position = 0
 
         for element in xrange(0, count):
             if element > 0: