Fix trailing whitespace and space before tab in indent

everywhere but in LICENCE which has a separate fixup branch; keep docs/make.bat in CR-LF line endings)

biscuit/core/templates/registration/login.html

@@ -19,6 +19,6 @@
   {% bootstrap_form form %}
   <button type="submit" class="btn btn-dark">
     {% blocktrans %}Login{% endblocktrans %}
-  </button>  
+  </button>
  </form>
 {% endblock %}