Fix run_test.sh when WCT_HEADLESS_MODE is not defined

When this WCT_HEADLESS_MODE is not defined, headless
tests are started by the default.

To fix this we look for the value 1 in WCT_HEADLESS_MODE rather
then making sure it does not equal 0.

Change-Id: I9910c60ac8338d7e57a194219fe763f46e7e02db
diff --git a/polygerrit-ui/app/wct.conf.js b/polygerrit-ui/app/wct.conf.js
index 0e53adb..1a9300e 100644
--- a/polygerrit-ui/app/wct.conf.js
+++ b/polygerrit-ui/app/wct.conf.js
@@ -27,7 +27,7 @@
 */
 
 const headless = 'WCT_HEADLESS_MODE' in process.env ?
-  process.env['WCT_HEADLESS_MODE'] !== '0' : false;
+  process.env['WCT_HEADLESS_MODE'] === '1' : false;
 
 const headlessBrowserOptions = {
   chrome: ['start-maximized', 'headless', 'disable-gpu', 'no-sandbox'],