Remove extra quotes around change identifiers in documentation

The documentation formats the recommended change identifier as

  "'<project>~<changeNumber>'"

which makes people think that the apostrophes must be included, which is
not the case.

Since the other examples in this section use double quotes only drop the
single quotes around change identifiers and keep the double quotes.

Release-Notes: skip
Change-Id: Ie32be7a8c0ca0ea125cf3900f2fdd7f67c228a4d
Signed-off-by: Edwin Kempin <ekempin@google.com>
diff --git a/Documentation/rest-api-changes.txt b/Documentation/rest-api-changes.txt
index e8f9a6a..b9b3b19 100644
--- a/Documentation/rest-api-changes.txt
+++ b/Documentation/rest-api-changes.txt
@@ -6676,20 +6676,20 @@
 [[change-id]]
 === \{change-id\}
 Identifier that uniquely identifies one change. It contains the URL-encoded
-project name as well as the change number: "'$$<project>~<changeNumber>$$'"
+project name as well as the change number: "$$<project>~<changeNumber>$$"
 
 ==== Alternative identifiers
 Gerrit also supports an array of other change identifiers.
 
 [NOTE]
 Even though these identifiers will work in the majority of cases it is highly
-recommended to use "'$$<project>~<changeNumber>$$'" whenever possible.
+recommended to use "$$<project>~<changeNumber>$$" whenever possible.
 Since these identifiers require additional lookups from index and caches, to
-be translated to the "'$$<project>~<changeNumber>$$'" identifier, they
+be translated to the "$$<project>~<changeNumber>$$" identifier, they
 may result in both false-positives and false-negatives.
 Furthermore the additional lookup mean that they come with a performance penalty.
 
-* an ID of the change in the format "'$$<project>~<branch>~<Change-Id>$$'",
+* an ID of the change in the format "$$<project>~<branch>~<Change-Id>$$",
   where for the branch the `refs/heads/` prefix can be omitted
   ("$$myProject~master~I8473b95934b5732ac55d26311a706c9c2bde9940$$")
 * a Change-Id if it uniquely identifies one change