fix: Safeguard IE against console.log

Shield a reference to `window.console.log` with a simple if statement.
Fix the ability to use this page in IE without the inspector open. This
 was particularly an issue for developers running karma from within a
Microsoft-based IDE. The log message will just be swallowed on
environments that don't support `window.console`.

Closes karma-runner#1209

static/debug.html

@@ -23,7 +23,7 @@
         if (info.dump && window.console) window.console.log(info.dump);
       },
       complete: function() {
-        window.console.log('Skipped ' + this.skipped + ' tests');
+        if (window.console) window.console.log('Skipped ' + this.skipped + ' tests');
       },
       store: function() {},
       skipped: 0,