[closebrackets addon] Avoid annoying behavior when closing a triple-quoted string

Issue #5177

addon/edit/closebrackets.js

@@ -129,8 +129,8 @@
         else
           curType = "skip";
       } else if (identical && cur.ch > 1 && triples.indexOf(ch) >= 0 &&
-                 cm.getRange(Pos(cur.line, cur.ch - 2), cur) == ch + ch &&
-                 (cur.ch <= 2 || cm.getRange(Pos(cur.line, cur.ch - 3), Pos(cur.line, cur.ch - 2)) != ch)) {
+                 cm.getRange(Pos(cur.line, cur.ch - 2), cur) == ch + ch) {
+        if (cur.ch > 2 && /\bstring/.test(cm.getTokenTypeAt(Pos(cur.line, cur.ch - 2)))) return CodeMirror.Pass;
         curType = "addFour";
       } else if (identical) {
         var prev = cur.ch == 0 ? " " : cm.getRange(Pos(cur.line, cur.ch - 1), cur)