[BUG]-SSH Client can throw a null ref exception if retry times are too short

[andrew-welker]

Describe the bug
Probably due to threading issues, the GenericSSHClient can throw a null reference exception if the retry time for reconnecting on connection loss is too short. 'Too short' in this case is less than 10 seconds.

Stacktrace

[15:56:52.000]App 1:Exception: NullReferenceException
[15:56:52.000]App 1:Stack Trace:    at PepperDash.Core.GenericSshClient.SendText(String text)
   at UserModule_PDT_SSHCLIENT_V1_1_3.UserModuleClass_PDT_SSHCLIENT_V1_1_3.TX_OnChange_5(Object __EventInfo__)
   at Amib.Threading.Internal.WorkItem.n()
   at Amib.Threading.Internal.WorkItem.Execute()
   at Amib.Threading.SmartThreadPool.f(WorkItem A_0)
   at Amib.Threading.SmartThreadPool.r