store maxSendQBytes in a uint32 to avoid alignment problems

The sync.atomic documentation says:

"On both ARM and x86-32, it is the caller's responsibility to arrange
for 64-bit alignment of 64-bit words accessed atomically."

irc/getters.go

@@ -10,11 +10,11 @@ import (
 )
 
 func (server *Server) MaxSendQBytes() int {
-	return int(atomic.LoadUint64(&server.maxSendQBytes))
+	return int(atomic.LoadUint32(&server.maxSendQBytes))
 }
 
 func (server *Server) SetMaxSendQBytes(m int) {
-	atomic.StoreUint64(&server.maxSendQBytes, uint64(m))
+	atomic.StoreUint32(&server.maxSendQBytes, uint32(m))
 }
 
 func (server *Server) ISupport() *isupport.List {

irc/server.go

@@ -109,7 +109,7 @@ type Server struct {
 	limits                     Limits
 	listeners                  map[string]*ListenerWrapper
 	logger                     *logger.Manager
-	maxSendQBytes              uint64
+	maxSendQBytes              uint32
 	monitorManager             *MonitorManager
 	motdLines                  []string
 	name                       string