prevent warnings to be treated as fatal errors in py++

Author: mamoll

pygccxml/parser/source_reader.py

@@ -153,8 +153,7 @@ def create_xml_file( self, header, destination=None ):
             process = subprocess.Popen( args=command_line
                                         , shell=True
                                         , stdin=subprocess.PIPE
-                                        , stdout=subprocess.PIPE
-                                        , stderr=subprocess.STDOUT )
+                                        , stdout=subprocess.PIPE )
             process.stdin.close()
 
             gccxml_reports = []