Change logging of priority plugin name loaded from verbose() to debug()

This fixes a problem running test24.2 with priority/basic

src/plugins/priority/basic/priority_basic.c

@@ -92,7 +92,7 @@ const uint32_t plugin_version	= 100;
  */
 int init ( void )
 {
-	verbose("%s loaded", plugin_name);
+	debug("%s loaded", plugin_name);
 	return SLURM_SUCCESS;
 }
 

src/plugins/priority/multifactor/priority_multifactor.c

@@ -1032,7 +1032,7 @@ int init ( void )
 
 	xfree(temp);
 
-	verbose("%s loaded", plugin_name);
+	debug("%s loaded", plugin_name);
 	return SLURM_SUCCESS;
 }