Fix h2mux close check

go.mod

@@ -28,7 +28,7 @@ require (
 	github.com/sagernet/gvisor v0.0.0-20250325023245-7a9c0f5725fb
 	github.com/sagernet/quic-go v0.52.0-beta.1
 	github.com/sagernet/sing v0.7.5
-	github.com/sagernet/sing-mux v0.3.2
+	github.com/sagernet/sing-mux v0.3.3
 	github.com/sagernet/sing-quic v0.5.0-beta.3
 	github.com/sagernet/sing-shadowsocks v0.2.8
 	github.com/sagernet/sing-shadowsocks2 v0.2.1

go.sum

@@ -169,8 +169,8 @@ github.com/sagernet/quic-go v0.52.0-beta.1/go.mod h1:OV+V5kEBb8kJS7k29MzDu6oj9Gy
 github.com/sagernet/sing v0.6.9/go.mod h1:ARkL0gM13/Iv5VCZmci/NuoOlePoIsW0m7BWfln/Hak=
 github.com/sagernet/sing v0.7.5 h1:gNMwZCLPqR+4e0g6dwi0sSsrvOmoMjpZgqxKsuJZatc=
 github.com/sagernet/sing v0.7.5/go.mod h1:ARkL0gM13/Iv5VCZmci/NuoOlePoIsW0m7BWfln/Hak=
-github.com/sagernet/sing-mux v0.3.2 h1:meZVFiiStvHThb/trcpAkCrmtJOuItG5Dzl1RRP5/NE=
-github.com/sagernet/sing-mux v0.3.2/go.mod h1:pht8iFY4c9Xltj7rhVd208npkNaeCxzyXCgulDPLUDA=
+github.com/sagernet/sing-mux v0.3.3 h1:YFgt9plMWzH994BMZLmyKL37PdIVaIilwP0Jg+EcLfw=
+github.com/sagernet/sing-mux v0.3.3/go.mod h1:pht8iFY4c9Xltj7rhVd208npkNaeCxzyXCgulDPLUDA=
 github.com/sagernet/sing-quic v0.5.0-beta.3 h1:X/acRNsqQNfDlmwE7SorHfaZiny5e67hqIzM/592ric=
 github.com/sagernet/sing-quic v0.5.0-beta.3/go.mod h1:SAv/qdeDN+75msGG5U5ZIwG+3Ua50jVIKNrRSY8pkx0=
 github.com/sagernet/sing-shadowsocks v0.2.8 h1:PURj5PRoAkqeHh2ZW205RWzN9E9RtKCVCzByXruQWfE=