Add trailing period on "This reverts commit ..." line

When a commit is reverted with the Web UI, the generated commit
message includes the line "This reverts commit <sha1>" without a
trailing period.

However, if the same revert is done manually from the command line
with `git revert`, the generated commit message includes the line
"This reverts commit <sha1>." with a trailing period.

Update the message generated when reverting from the Web UI to
include the trailing period on the line.

Change-Id: Iacb09a25bce2335ea65ad46d2676828cb402eb1d
diff --git a/gerrit-gwtui/src/main/java/com/google/gerrit/client/changes/ChangeMessages.properties b/gerrit-gwtui/src/main/java/com/google/gerrit/client/changes/ChangeMessages.properties
index ffa749d..caaf3bf 100644
--- a/gerrit-gwtui/src/main/java/com/google/gerrit/client/changes/ChangeMessages.properties
+++ b/gerrit-gwtui/src/main/java/com/google/gerrit/client/changes/ChangeMessages.properties
@@ -5,7 +5,7 @@
 changesMergedInProject = Merged Changes In {0}
 changesAbandonedInProject = Abandoned Changes In {0}
 
-revertChangeDefaultMessage = Revert \"{0}\"\n\nThis reverts commit {1}
+revertChangeDefaultMessage = Revert \"{0}\"\n\nThis reverts commit {1}.
 
 changeScreenTitleId = Change {0}
 outdatedHeader = Change depends on {0} outdated change(s) and should be rebased on the latest patch sets.
diff --git a/gerrit-server/src/main/resources/com/google/gerrit/server/change/ChangeMessages.properties b/gerrit-server/src/main/resources/com/google/gerrit/server/change/ChangeMessages.properties
index 11384a1..f05f23b 100644
--- a/gerrit-server/src/main/resources/com/google/gerrit/server/change/ChangeMessages.properties
+++ b/gerrit-server/src/main/resources/com/google/gerrit/server/change/ChangeMessages.properties
@@ -1,6 +1,6 @@
 # Changes to this file should also be made in
 # gerrit-gwtui/src/main/java/com/google/gerrit/client/changes/ChangeMessages.properties
-revertChangeDefaultMessage = Revert \"{0}\"\n\nThis reverts commit {1}
+revertChangeDefaultMessage = Revert \"{0}\"\n\nThis reverts commit {1}.
 reviewerNotFound = {0} does not identify a registered user or group
 
 groupIsNotAllowed =  The group {0} cannot be added as reviewer.