CLEANUP: connection: reduce the with of the mux dump output

In "haproxy -vv" we produce a list of available muxes with their
capabilities, but that list is often quite large for terminals due
to excess of spaces, so let's reduce them a bit to make the output
more readable.
diff --git a/src/connection.c b/src/connection.c
index 7d41471..2302fd9 100644
--- a/src/connection.c
+++ b/src/connection.c
@@ -1605,7 +1605,7 @@
 		else
 			side = "NONE";
 
-		fprintf(out, " %15s : mode=%-10s side=%-8s  mux=%-8s flags=",
+		fprintf(out, " %10s : mode=%-5s side=%-6s mux=%-5s flags=",
 			(proto.len ? proto.ptr : "<default>"), mode, side, item->mux->name);
 
 		done = 0;