MINOR: mux-h1: make the mux_h1_ops struct static

It was needlessly exported while it's only used inside the mux.
diff --git a/src/mux_h1.c b/src/mux_h1.c
index d4d3eb8..17674c7 100644
--- a/src/mux_h1.c
+++ b/src/mux_h1.c
@@ -2337,7 +2337,7 @@
 /****************************************/
 
 /* The mux operations */
-const struct mux_ops mux_h1_ops = {
+static const struct mux_ops mux_h1_ops = {
 	.init        = h1_init,
 	.wake        = h1_wake,
 	.attach      = h1_attach,