Delete repeated subtitle in documentation

In the 'Rule base configuration' documentation "Action: add-comment"
subtitle was repeated just before the "Action: add-velocity-comment"
which can be confusing.

Delete the repeated subtitle.

Change-Id: I8fc1ec62d41ac885c14ec6a6fccd897f0ea8304e

src/main/resources/Documentation/config-rulebase-common.md

diff --git a/src/main/resources/Documentation/config-rulebase-common.md b/src/main/resources/Documentation/config-rulebase-common.md
index fb053c4..ed2946c 100644
--- a/src/main/resources/Documentation/config-rulebase-common.md
+++ b/src/main/resources/Documentation/config-rulebase-common.md
@@ -534,9 +534,6 @@
 (abandoner, merger, ...), the change's subject, a reason (if one has
 been given), and a link to the change.
 
-[action-add-comment]: #action-add-comment
-### <a name="action-add-comment">Action: add-comment</a>
-
 [action-add-velocity-comment]: #action-add-velocity-comment
 ### <a name="action-add-velocity-comment">Action: add-velocity-comment</a>