Loosen strict parsing requirement for desktop files

There are other desktop-looking files, for instance those having to do
with MIME typess, that would benefit from being able to be read by this
function.  It helps to have some flexibility.
* lisp/xdg.el (xdg-desktop-read-file): Remove an error condition.
* test/lisp/xdg-tests.el: Remove a test.

lisp/xdg.el

@@ -197,8 +197,6 @@ Optional argument GROUP defaults to the string \"Desktop Entry\"."
     (unless (looking-at xdg-desktop-group-regexp)
       (error "Expected group name!  Instead saw: %s"
              (buffer-substring (point) (point-at-eol))))
-    (unless (equal (match-string 1) "Desktop Entry")
-      (error "Wrong first group: %s" (match-string 1)))
     (when group
       (while (and (re-search-forward xdg-desktop-group-regexp nil t)
                   (not (equal (match-string 1) group)))))

test/lisp/xdg-tests.el

@@ -40,9 +40,6 @@
     (should (equal (gethash "Name" tab1) "Test"))
     (should (eq 'default (gethash "Exec" tab1 'default)))
     (should (equal "frobnicate" (gethash "Exec" tab2))))
-  (should-error
-   (xdg-desktop-read-file
-    (expand-file-name "wrong.desktop" xdg-tests-data-dir)))
   (should-error
    (xdg-desktop-read-file
     (expand-file-name "malformed.desktop" xdg-tests-data-dir)))