Check mode fix for ec2_group module (#2184)

The default VPC egress rules was being left in the egress rules for
purging in check mode.  This ensures that the module returns the correct
change state during check mode.

cloud/amazon/ec2_group.py

@@ -426,20 +426,21 @@ def main():
                                     src_group_id=grantGroup,
                                     cidr_ip=thisip)
                         changed = True
-        elif vpc_id and not module.check_mode:
+        elif vpc_id:
             # when using a vpc, but no egress rules are specified,
             # we add in a default allow all out rule, which was the
             # default behavior before egress rules were added
             default_egress_rule = 'out--1-None-None-None-0.0.0.0/0'
             if default_egress_rule not in groupRules:
-                ec2.authorize_security_group_egress(
-                    group_id=group.id,
-                    ip_protocol=-1,
-                    from_port=None,
-                    to_port=None,
-                    src_group_id=None,
-                    cidr_ip='0.0.0.0/0'
-                )
+                if not module.check_mode:
+                    ec2.authorize_security_group_egress(
+                        group_id=group.id,
+                        ip_protocol=-1,
+                        from_port=None,
+                        to_port=None,
+                        src_group_id=None,
+                        cidr_ip='0.0.0.0/0'
+                    )
                 changed = True
             else:
                 # make sure the default egress rule is not removed