infinitepush: don't force ipv6 while connecting to mysql server

Facebook internally enforces this but looks like we can't force this for pur
users.

Differential Revision: https://phab.mercurial-scm.org/D2992

hgext/infinitepush/sqlindexapi.py

@@ -60,8 +60,7 b' class sqlindexapi(indexapi.indexapi):'
         retry = 3
         while True:
             try:
-                self.sqlconn = mysql.connector.connect(
-                    force_ipv6=True, **self.sqlargs)
+                self.sqlconn = mysql.connector.connect(**self.sqlargs)
 
                 # Code is copy-pasted from hgsql. Bug fixes need to be
                 # back-ported!