fix (SE): check the protocol only after checking the plugins when checking the occupancy

Author: chaen

src/DIRAC/Resources/Storage/StorageElement.py

@@ -438,10 +438,6 @@ def getOccupancy(self, unit="MB", **kwargs):
 
             kwargs["occupancyLFN"] = occupancyLFN
 
-        filteredPlugins = self.__filterPlugins("getOccupancy")
-        if not filteredPlugins:
-            return S_ERROR(errno.EPROTONOSUPPORT, "No storage plugins to query the occupancy")
-
         # Call occupancy plugin if requested
         occupancyPlugin = self.options.get("OccupancyPlugin")
         if occupancyPlugin:
@@ -459,6 +455,10 @@ def getOccupancy(self, unit="MB", **kwargs):
             except Exception as e:
                 return S_ERROR(f"Occupancy plugin failed: {str(e)}")
 
+        filteredPlugins = self.__filterPlugins("getOccupancy")
+        if not filteredPlugins:
+            return S_ERROR(errno.EPROTONOSUPPORT, "No storage plugins to query the occupancy")
+
         # Try all of the storages one by one
         for storage in filteredPlugins:
             # The result of the plugin is always in B