Fixed typo in metric description

Change-Id: I5c144afdea8f269a60c8fccb2297a6ee862c8358

src/main/resources/Documentation/metrics.md

diff --git a/src/main/resources/Documentation/metrics.md b/src/main/resources/Documentation/metrics.md
index 6fd6cf2..055b2bd 100644
--- a/src/main/resources/Documentation/metrics.md
+++ b/src/main/resources/Documentation/metrics.md
@@ -44,7 +44,7 @@
   error and none of the operations took place; a partial failure is when
   some of the operations in the tasks succeeded but other failed.
 
-- `retrying`: (counter) number of tasks being retired for execution.
+- `retrying`: (counter) number of tasks being retried for execution.
 
 - `not_scheduled`: (counter) number of tasks which have been discarded before
   being executed, because redundant (duplicate of existing scheduled tasks)