Fix spelling mistake in the 2.7 release notes

Change-Id: I1ca877df754d5aa8937da25343ad973dd2cbedeb

ReleaseNotes/ReleaseNotes-2.7.txt

diff --git a/ReleaseNotes/ReleaseNotes-2.7.txt b/ReleaseNotes/ReleaseNotes-2.7.txt
index 9a29065..c08ffa6 100644
--- a/ReleaseNotes/ReleaseNotes-2.7.txt
+++ b/ReleaseNotes/ReleaseNotes-2.7.txt
@@ -106,7 +106,7 @@
 * link:https://code.google.com/p/gerrit/issues/detail?id=667[Issue 667]:
 Highlight patch sets that have drafts.
 +
-Patch sets having unpublished draft comments are higlighted with an icon.
+Patch sets having unpublished draft comments are highlighted with an icon.
 
 * Option to show relative times in change tables.
 +