Roll tools/swarming_client/ to b61a1802f5ef4bb8c7b81060cc80add47e6cf302.

$ git log 1b7bfeca3..b61a1802f --date=short --format='%ad %ae %s' | sed 's/@chromium\.org//'
2015-03-09 maruel Ignore command from included .isolate when the current one define a command.
2015-02-26 maruel Reduce ereporter2 spam on file locking on Windows.

R=vadimsh@chromium.org
BUG=440882

Review URL: https://codereview.chromium.org/986423002

Cr-Commit-Position: refs/heads/master@{#319780}

DEPS

@@ -54,7 +54,7 @@ vars = {
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling swarming_client
   # and whatever else without interference from each other.
-  'swarming_revision': '1b7bfeca33abce319356fd1835a5cd2f74f1916a',
+  'swarming_revision': 'b61a1802f5ef4bb8c7b81060cc80add47e6cf302',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling ANGLE
   # and whatever else without interference from each other.