Corrected restart throttling documentation.

The documentation said that the maximum throttle time was 60 seconds
whereas in fact it is 256 seconds.  The documentation now describes
it as four minutes.

README.txt

@@ -72,11 +72,12 @@ keep trying, pausing between each attempt, until the service is successfully
 started or you send it a stop signal.
 
 NSSM will pause an increasingly longer time between subsequent restart attempts
-if the service fails to start in a timely manner, up to a maximum of 60 seconds.
-This is so it does not consume an excessive amount of CPU time trying to start
-a failed application over and over again.  If you identify the cause of the
-failure and don't want to wait you can use the Windows service console to
-send a continue signal to NSSM and it will retry within a few seconds.
+if the service fails to start in a timely manner, up to a maximum of four
+minutes.  This is so it does not consume an excessive amount of CPU time trying
+to start a failed application over and over again.  If you identify the cause
+of the failure and don't want to wait you can use the Windows service console
+(where the service will be shown in Paused state) to send a continue signal to
+NSSM and it will retry within a few seconds.
 
 NSSM will look in the registry under
 HKLM\SYSTEM\CurrentControlSet\Services\<service>\Parameters\AppExit for