fix(network): disable MPTCP by default (#14258)

Set multipathtcp=0 in the core and agent module defaults so Linux listeners use standard TCP without requiring service environment changes.

Co-authored-by: zhengkunwang223 <31820853+zhengkunwang223@users.noreply.github.com>

agent/go.mod

@@ -2,6 +2,8 @@ module github.com/1Panel-dev/1Panel/agent
 
 go 1.27.3
 
+godebug multipathtcp=0
+
 replace github.com/go-acme/lego/v5 => github.com/1Panel-dev/lego/v5 v5.3.1
 
 require (

core/go.mod

@@ -2,6 +2,8 @@ module github.com/1Panel-dev/1Panel/core
 
 go 1.27.3
 
+godebug multipathtcp=0
+
 require (
 	github.com/beevik/etree v1.7.0
 	github.com/coreos/go-oidc/v3 v3.20.0