Fix spelling mistakes in release notes

Change-Id: Ieea1e0703f8b1814eee55a19f3af5890ca2ecd0b
diff --git a/ReleaseNotes/ReleaseNotes-2.1.7.2.txt b/ReleaseNotes/ReleaseNotes-2.1.7.2.txt
index 9172b4a..802f1c7 100644
--- a/ReleaseNotes/ReleaseNotes-2.1.7.2.txt
+++ b/ReleaseNotes/ReleaseNotes-2.1.7.2.txt
@@ -25,7 +25,7 @@
 * Fix API breakage on ChangeDetailService
 +
 Version 2.1.7 broke the Gerrit Code Review plugin for Mylyn Reviews
-due to an accidential signature change of one of the remote JSON
+due to an accidental signature change of one of the remote JSON
 APIs. The ChangeDetailService.patchSetDetail() method is back to the
 old signature and a new patchSetDetail2() method has been added to
 handle the newer calling convention used in some contexts of the