Allow running rpc_bind.py --nonloopback test without IPv6

Author: kristapsk

test/functional/rpc_bind.py

@@ -75,7 +75,7 @@ def run_test(self):
 
         self.log.info("Check for ipv6")
         have_ipv6 = test_ipv6_local()
-        if not have_ipv6 and not self.options.run_ipv4:
+        if not have_ipv6 and not (self.options.run_ipv4 or self.options.run_nonloopback):
             raise SkipTest("This test requires ipv6 support.")
 
         self.log.info("Check for non-loopback interface")