Fix table export to docbook when field contains a backslash

* lisp/org-docbook.el (org-export-docbook-finalize-table): Do literal
replacements.

lisp/org-docbook.el

@@ -1367,7 +1367,7 @@ TABLE is a string containing the HTML code generated by
 				     (match-string 1 table)
 				     (match-string 4 table)
 				     "</table>")
-			     nil nil table)
+			     nil t table)
 	    table))
     ;; Change <table> into <informaltable> if caption does not exist.
     (if (string-match
@@ -1377,7 +1377,7 @@ TABLE is a string containing the HTML code generated by
 			       (match-string 1 table-with-label)
 			       (match-string 3 table-with-label)
 			       "</informaltable>")
-		       nil nil table-with-label)
+		       nil t table-with-label)
       table-with-label)))
 
 ;; Note: This function is very similar to