static: Use SVG logo during first wizard welcome step

- This removes the need to ship a 67K file and scales better.

- Rename the file to have lowercase chars only for consistency.

Tests performed:

- Goto home page, see the logo at the bottom properly displayed.

- Goto the first wizard welcome page, notice that the logo is displayed. Also
the dimensions of the image are same as without the change.

Signed-off-by: Sunil Mohan Adapa <sunil@medhas.org>
Reviewed-by: James Valleroy <jvalleroy@mailbox.org>

plinth/modules/first_boot/templates/firstboot_welcome.html

@@ -21,7 +21,7 @@
 
 {% block content %}
   <div class="logo">
-    <img class="firstboot" src="{% static 'theme/img/FreedomBox-logo-standard.png' %}"
+    <img class="firstboot" src="{% static 'theme/img/freedombox-logo-standard.svg' %}"
          alt="{{ box_name }}" />
   </div>
 

plinth/templates/index.html

@@ -99,7 +99,7 @@
 
   <p>
     <a href="{% url 'index' %}" title="{{ box_name }}">
-      <img class="footer-logo" src="{% static 'theme/img/FreedomBox-logo-standard.svg' %}"
+      <img class="footer-logo" src="{% static 'theme/img/freedombox-logo-standard.svg' %}"
            alt="{{ box_name }}" />
     </a>
   </p>