oc-biblatex: Remove \relax hack after multicite commands

* lisp/oc-biblatex.el (org-cite-biblatex--multi-arguments): Do not try
to be smart and add \relax{} after multicite commands, as it breaks
csquotes.

Reported-by: Zac E <zac.endter@gmail.com>
<https://list.orgmode.org/8E381952-2AE5-45BF-B142-91DB4B18A26E@gmail.com/T/#t>

lisp/oc-biblatex.el

@@ -164,12 +164,7 @@ INFO is the export state, as a property list."
             (mapconcat (lambda (r)
                          (org-cite-biblatex--atomic-arguments (list r) info))
                        (org-cite-get-references citation)
-                       "")
-            ;; According to BibLaTeX manual, left braces or brackets
-            ;; following a multicite command could be parsed as other
-            ;; arguments. So we stop any further parsing by inserting
-            ;; a \relax unconditionally.
-            "\\relax")))
+                       ""))))
 
 (defun org-cite-biblatex--command (citation info base &optional multi no-opt)
   "Return biblatex command using BASE name for CITATION object.