BUG19711759: Fix Pylint issue in network module

We fix Pylint W0633 warning in mysql.connector.network module
with message "Attempting to unpack a non-sequence define at line 438".

Author: peeyushgupta

lib/mysql/connector/network.py

@@ -435,7 +435,7 @@ def open_connection(self):
         """Open the TCP/IP connection to the MySQL server
         """
         # Get address information
-        addrinfo = None
+        addrinfo = [None] * 5
         try:
             addrinfos = socket.getaddrinfo(self.server_host,
                                            self.server_port,
@@ -449,10 +449,10 @@ def open_connection(self):
                 elif info[0] == socket.AF_INET:
                     addrinfo = info
                     break
-            if self.force_ipv6 and not addrinfo:
+            if self.force_ipv6 and addrinfo[0] is None:
                 raise errors.InterfaceError(
                     "No IPv6 address found for {0}".format(self.server_host))
-            if not addrinfo:
+            if addrinfo[0] is None:
                 addrinfo = addrinfos[0]
         except IOError as err:
             raise errors.InterfaceError(