Fix: OP indicator was being added to "last updated" field

If a thread had been edited, the username added in the "last updated"
field was being misidentified also as the OP username, and so the OP
indicator was being injected there too.

This commit fixes this issue by checking that the username is not inside

Change-Id: I4c697bf67dd56f1f2cfc0980b6cee9ec46713c58
diff --git a/src/injections/profileindicator_inject.js b/src/injections/profileindicator_inject.js
index fa0415b..3cf3dab 100644
--- a/src/injections/profileindicator_inject.js
+++ b/src/injections/profileindicator_inject.js
@@ -338,6 +338,7 @@
         mutation.addedNodes.forEach(function(node) {
           if (node.tagName == 'A' && ('href' in node) &&
               CCProfileRegex.test(node.href) &&
+              !isElementInside(node, 'EC-RELATIVE-TIME') &&
               isElementInside(node, 'EC-QUESTION') && ('children' in node) &&
               node.children.length == 0) {
             getOptionsAndHandleIndicators(node, true);