CLEANUP: server: fix cosmetic of error message on sni parsing

Fix memprintf used in server_parse_sni_expr. Error messages should not
be ending with a newline as it will be inserted in the parent function
on the ha_alert invocation.
diff --git a/src/server.c b/src/server.c
index be4e6e1..6553c96 100644
--- a/src/server.c
+++ b/src/server.c
@@ -1851,7 +1851,7 @@
 	if (!(expr->fetch->val & SMP_VAL_BE_SRV_CON)) {
 		memprintf(err, "error detected while parsing sni expression : "
 		          " fetch method '%s' extracts information from '%s', "
-		          "none of which is available here.\n",
+		          "none of which is available here.",
 		          newsrv->sni_expr, sample_src_names(expr->fetch->use));
 		return ERR_ALERT | ERR_FATAL;
 	}