Maya Render Settings validator prefix confusion
 ## Issue

There is a little issue with Render Settings validator that if `Merge AOV` is selected,  This validator will complain about superfluous `<RenderPass>` token. But If that token is correctly removed, Render Settings validator will issue warning about image prefix being different than the default one.

[cuID:296qnmz]
diff --git a/openpype/hosts/maya/plugins/publish/validate_rendersettings.py b/openpype/hosts/maya/plugins/publish/validate_rendersettings.py
index ba6c1397ab..1dab3274a0 100644
--- a/openpype/hosts/maya/plugins/publish/validate_rendersettings.py
+++ b/openpype/hosts/maya/plugins/publish/validate_rendersettings.py
@@ -94,6 +94,7 @@ class ValidateRenderSettings(pyblish.api.InstancePlugin):
     def get_invalid(cls, instance):
 
         invalid = False
+        multipart = False
 
         renderer = instance.data['renderer']
         layer = instance.data['setMembers']
@@ -113,6 +114,7 @@ class ValidateRenderSettings(pyblish.api.InstancePlugin):
             "{aov_separator}", instance.data.get("aovSeparator", "_"))
 
         required_prefix = "maya/<scene>"
+        default_prefix = cls.ImagePrefixTokens[renderer]
 
         if not anim_override:
             invalid = True
@@ -213,14 +215,16 @@ class ValidateRenderSettings(pyblish.api.InstancePlugin):
                     cls.log.error("Wrong image prefix [ {} ] - "
                                   "You can't use '<renderpass>' token "
                                   "with merge AOVs turned on".format(prefix))
+                default_prefix = re.sub(
+                    cls.R_AOV_TOKEN, "", default_prefix)
+                # remove aov token from prefix to pass validation
+                default_prefix = default_prefix.split("{aov_separator}")[0]
             elif not re.search(cls.R_AOV_TOKEN, prefix):
                 invalid = True
                 cls.log.error("Wrong image prefix [ {} ] - "
                               "doesn't have: '<renderpass>' or "
                               "token".format(prefix))
 
-        # prefix check
-        default_prefix = cls.ImagePrefixTokens[renderer]
         default_prefix = default_prefix.replace(
             "{aov_separator}", instance.data.get("aovSeparator", "_"))
         if prefix.lower() != default_prefix.lower():
['openpype/hosts/maya/plugins/publish/validate_rendersettings.py']