Set commit message tabindex

This way it is just a tab from suggest and save buttons.

Issue #415

weblate/html/translate.html

@@ -170,7 +170,7 @@
 {% if perms.trans.save_translation %}
 <div class="menu-float tooltip">
 <div class="tooltip-content">{% trans "Additional text to include in the commit message." %}</div>
-{% trans "Commit message:" %} <input type="text" name="commit_message" class="commit_message" value="{{ unit.translation.commit_message }}" />
+{% trans "Commit message:" %} <input type="text" name="commit_message" class="commit_message" tabindex="152" value="{{ unit.translation.commit_message }}" />
 </div>
 {% endif %}
 </td></tr>