gnu: emacs-ccls: Revise license.

* gnu/packages/emacs-xyz.scm (emacs-ccls): Change license to reflect
  MIT/Expat-style license.

gnu/packages/emacs-xyz.scm

@@ -15915,7 +15915,7 @@ Pandoc, the document-conversion tool.")
       (synopsis "Emacs support for the @code{ccls} language server")
       (description "This package extends @code{lsp-mode} to work with @code{C}
 and @code{C++} files through the @code{ccls} language server.")
-      (license license:bsd-3))))
+      (license license:expat))))
 
 (define-public emacs-org-brain
   (package