BUG/MINOR: mux-fcgi/trace: fix wrong set of trace flags in fcgi_strm_add_eom()

A typo resulted in '||' being used to concatenate trace flags, which will
only set flag of value '1' there. Noticed by clang 10 and reported in
issue #588.

No backport is needed, this trace was added in 2.2-dev.
diff --git a/src/mux_fcgi.c b/src/mux_fcgi.c
index b092038..2f712f3 100644
--- a/src/mux_fcgi.c
+++ b/src/mux_fcgi.c
@@ -3288,7 +3288,7 @@
 {
 	int ret;
 
-	TRACE_ENTER(FCGI_EV_RSP_DATA||FCGI_EV_RSP_EOM, fstrm->fconn->conn, fstrm,, (size_t[]){max});
+	TRACE_ENTER(FCGI_EV_RSP_DATA|FCGI_EV_RSP_EOM, fstrm->fconn->conn, fstrm,, (size_t[]){max});
 	ret = h1_parse_msg_eom(h1m, htx, max);
 	if (!ret) {
 		TRACE_DEVEL("leaving on missing data or error", FCGI_EV_RSP_DATA|FCGI_EV_RSP_EOM, fstrm->fconn->conn, fstrm);