Have _CDB_UserQuotaInBytes() take precedence over parameter-based quota

Closes #16

scripts-available/CDB_Quota.sql

@@ -35,17 +35,16 @@ BEGIN
 
   IF dice < pbfact THEN
     RAISE DEBUG 'Checking quota on table % (dice:%, needed:<%)', TG_RELID::text, dice, pbfact;
+    BEGIN
+      qmax := public._CDB_UserQuotaInBytes();
+    EXCEPTION WHEN undefined_function THEN
       IF TG_NARGS > 1 THEN
         RAISE NOTICE 'Using quota specified via trigger parameter';
         qmax := TG_ARGV[1];
       ELSE
-      BEGIN
+        RAISE EXCEPTION 'Missing _CDB_UserQuotaInBytes(), and no quota provided as parameter';
-        qmax := public._CDB_UserQuotaInBytes();
-      EXCEPTION WHEN undefined_function THEN
-        RAISE WARNING 'Missing _CDB_UserQuotaInBytes(), assuming no quota';
-        qmax := 0;
-      END;
       END IF;
+    END;
 
     IF qmax = 0 THEN
       RETURN NEW;