Bug 1867974 - Bump Enigmail version and typo fixes. r=frg

src/releases/seamonkey2.53.18/index.en.html

@@ -92,7 +92,7 @@ for new information.
   <li>Use BugSplat for SeaMonkey crash reporting <a
     href="https://bugzilla.mozilla.org/show_bug.cgi?id=1835524">bug 1835524</a>.
   </li>
-  <li>Unify notifications and permissions in SeaMonkey<a
+  <li>Unify notifications and permissions in SeaMonkey <a
     href="https://bugzilla.mozilla.org/show_bug.cgi?id=1849526">bug 1849526</a>.
   </li>
 </ul>
@@ -104,7 +104,7 @@ The following bugs were fixed in our branch of the Gecko source code only:
   <li>Update the NSS and NSPR libraries to the esr 115 versions for the final
     2.53.18 release.
   </li>
-  <li>Allow building with system icu again in the final 2.53.18 release<a
+  <li>Allow building with system icu again in the final 2.53.18 release <a
     href="https://bugzilla.mozilla.org/show_bug.cgi?id=1864745">bug 1864745</a>.
   </li>
 </ul>
@@ -226,8 +226,8 @@ note the following warnings and advice regarding extensions:</p>
   </li>
   <li>For <b>Enigmail</b>, please refer to the
     <a href="https://enigmail.net/index.php/en/home">Enigmail</a> page.
-    <br>The latest supported version is 3.1.6
-    <a href="https://enigmail.net/download/release/3.1/enigmail-3.1.6-il.xpi">
+    <br>The latest supported version is 3.1.7
+    <a href="https://enigmail.net/download/release/3.1/enigmail-3.1.7-il.xpi">
     Enigmail</a>.
   </li>
   <li>Adblock Plus 2.9.1 may cause huge memory and CPU consumption and is not