Fix ipv6 skip condition

ipv6 skip condition moved under "skip_checks"
classmethod by https://review.opendev.org/#/c/715679/.
Here we correct the condition that checks whether IPv6
is enabled.

Change-Id: I39ac26fe035af81fbd4cb54d8096fc5d7afc2b0b
diff --git a/manila_tempest_tests/tests/scenario/manager_share.py b/manila_tempest_tests/tests/scenario/manager_share.py
index 23fc4c4..a2b9c65 100644
--- a/manila_tempest_tests/tests/scenario/manager_share.py
+++ b/manila_tempest_tests/tests/scenario/manager_share.py
@@ -61,7 +61,7 @@
         super(ShareScenarioTest, cls).skip_checks()
         if not CONF.service_available.manila:
             raise cls.skipException("Manila support is required")
-        if cls.ipv6_enabled and not CONF.share.run_ipv6_tests:
+        if cls.ip_version == 6 and not CONF.share.run_ipv6_tests:
             raise cls.skipException("IPv6 tests are disabled")
         if cls.protocol not in CONF.share.enable_protocols:
             message = "%s tests are disabled" % cls.protocol