Fix catastrophic error

mobile/src/main/java/be/mygod/vpnhotspot/net/DhcpWorkaround.kt

@@ -28,6 +28,7 @@ object DhcpWorkaround : SharedPreferences.OnSharedPreferenceChangeListener {
     val shouldEnable get() = app.pref.getBoolean(KEY_ENABLED, false)
     fun enable(enabled: Boolean) = GlobalScope.launch {
         val action = if (enabled) "add" else "del"
+        try {
             RootSession.use {
                 try {
                     it.exec("ip rule $action iif lo uidrange 0-0 lookup local_network priority 11000")
@@ -39,12 +40,13 @@ object DhcpWorkaround : SharedPreferences.OnSharedPreferenceChangeListener {
                             }) return@use
                     Timber.w(IOException("Failed to tweak dhcp workaround rule", e))
                     SmartSnackbar.make(e).show()
+                }
+            }
         } catch (e: Exception) {
             Timber.w(e)
             SmartSnackbar.make(e).show()
         }
     }
-    }
 
     override fun onSharedPreferenceChanged(sharedPreferences: SharedPreferences?, key: String?) {
         if (key == KEY_ENABLED) enable(shouldEnable)