Create socket on specific ipv4 address. (#2)

Not being specific here causes python3 to try an ipv6 address first which fails on kernels which do not contain the ipv6 module.
diff --git a/core/actionProxy/actionproxy.py b/core/actionProxy/actionproxy.py
index c68231f..8e43576 100644
--- a/core/actionProxy/actionproxy.py
+++ b/core/actionProxy/actionproxy.py
@@ -263,7 +263,7 @@
 
 def main():
     port = int(os.getenv('FLASK_PROXY_PORT', 8080))
-    server = WSGIServer(('', port), proxy, log=None)
+    server = WSGIServer(('0.0.0.0', port), proxy, log=None)
     server.serve_forever()
 
 if __name__ == '__main__':