Improve wording about invalid/missing rate limit config

Change-Id: I93db6e0e0b1420cb7f3a276625a15f73eaf5b00d
diff --git a/src/main/resources/Documentation/config.md b/src/main/resources/Documentation/config.md
index c8eaaea..161013f 100644
--- a/src/main/resources/Documentation/config.md
+++ b/src/main/resources/Documentation/config.md
@@ -210,7 +210,7 @@
 as if idle time would already have been accumulated.
 
 If a rate limit configuration value is invalid or missing for a group,
-the configuration entry gets ignored, and a warning is being logged.
+that value is ignored and a warning is logged.
 
 Example: