修复 mount -rB 可能导致的挂载权限问题

ss-tproxy

@@ -808,7 +808,7 @@ function dns_proxy {
 # Generated by ss-tproxy at $(date '+%F %T')
 nameserver 127.0.0.1
 EOF
-    mount -rB $resolv /etc/resolv.conf
+    mount -B $resolv /etc/resolv.conf
     rm -f $resolv &>/dev/null
 }