Fix a typo in a comment.

Bug: none
Change-Id: I156a2d2b7d8569e3a8fe7a17e09d52c859710ae6
Reviewed-on: https://chromium-review.googlesource.com/1179607Reviewed-by: Bruce Dawson <brucedawson@chromium.org>
Commit-Queue: Nico Weber <thakis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#584082}

build/timestamp.gni

@@ -13,7 +13,7 @@ if (is_official_build) {
 }
 
 # This will return a timestamp that's different each day (official builds)
-# of each month (regular builds).  Just rely on gn rerunning due to other
+# or each month (regular builds).  Just rely on gn rerunning due to other
 # changes to keep this up to date.  (Bots run gn on each build, and for devs
 # the timestamp being 100% accurate doesn't matter.)
 # See compute_build_timestamp.py for tradeoffs for picking the timestamp.