openWebsiteTriggerMessage can also be used for openTab

lib/Properties.hs

@@ -409,7 +409,7 @@ checkTileLayerProperty p@(Property name _value) = case name of
       requireProperty "playAudio"
     "openWebsiteTrigger" -> do
       isString p
-      requireProperty "openWebsite"
+      requireOneOf ["openWebsite", "openTab"]
       unlessHasProperty "openWebsiteTriggerMessage"
         $ suggest "set \"openWebsiteTriggerMessage\" to a custom message to \
                   \overwrite the default \"press SPACE to open Website\"."
@@ -496,6 +496,12 @@ checkTileLayerProperty p@(Property name _value) = case name of
         warnUnknown p knownTileLayerProperites
     where
       requireProperty req = propertyRequiredBy req name
+      requireOneOf names = do
+        context <- askContext
+        when (all (not . containsProperty context) names)
+          $ complain $ "property " <> prettyprint name <> " requires one of "
+                    <> prettyprint names
+
       isUnsupported = warn $ "property " <> name <> " is not (yet) supported by walint."
       deprecatedUseInstead instead =
         warn $ "property \"" <> name <> "\" is deprecated. Use \"" <> instead <> "\" instead."