Remove extra unescape call

Example: the code block arrives from summarize_test_report as

<pre><code class="language-diff">--- expected
+++ actual
@@ -1 +0,0 @@
-no output expected std::unique_ptr&lt;int&gt;</code></pre>

after the unescape call:

<pre><code class="language-diff">--- expected
+++ actual
@@ -1 +0,0 @@
-no output expected std::unique_ptr<int></code></pre>

So it gets displayed on the page as:

--- expected
+++ actual
@@ -1 +0,0 @@
-no output expected std::unique_ptr