Fix non-ASCII character in WPT webdriver

A non-ASCII character was introduced into
third_party/blink/web_tests/external/wpt/webdriver/tests/support/__init__.py
by the wpt roll
https://chromium-review.googlesource.com/c/chromium/src/+/2147959.
This causes a compilation failure in Python 2. Fix it.

TBR=smcgruer

Change-Id: I83180eb29b3ee05aedd282b96225745010f74150
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2149483Reviewed-by: Adam Rice <ricea@chromium.org>
Commit-Queue: Adam Rice <ricea@chromium.org>
Cr-Commit-Position: refs/heads/master@{#759171}

third_party/blink/web_tests/external/wpt/webdriver/tests/support/__init__.py

@@ -3,7 +3,7 @@ import sys
 from .merge_dictionaries import merge_dictionaries
 
 platform_name = {
-    # From Python version 3.3: On Linux, sys.platform doesn’t contain the major version anymore.
+    # From Python version 3.3: On Linux, sys.platform doesn't contain the major version anymore.
     # It is always 'linux'. See
     # https://docs.python.org/3/library/sys.html#sys.platform
     "linux": "linux",