Fix whitespace error

rebar.config.sample

@@ -161,5 +161,5 @@
 %% functions from undefined external function calls as those are in a
 %% generated module
 {xref_queries,
-  [{"(XC - UC) || (XU - X - B"
-    " - (\"ejabberd_logger\":\".*_msg\"/\"4\"))",[]}]}.
+ [{"(XC - UC) || (XU - X - B"
+   " - (\"ejabberd_logger\":\".*_msg\"/\"4\"))",[]}]}.