Update Set-ThrottlingPolicy.md

Added a line on the OWAMaxConcurrency bit

Author: angadsin

exchange/exchange-ps/exchange/Set-ThrottlingPolicy.md

@@ -1659,6 +1659,7 @@ Accept wildcard characters: False
 
 ### -OWAMaxConcurrency
 The OwaMaxConcurrency parameter specifies how many concurrent connections an Outlook on the web user can have against an Exchange server at one time. A connection is held from the moment a request is received until a response is sent in its entirety to the requestor. If users attempt to make more concurrent requests than their policy allows, the new connection attempt fails. However, the existing connections remain valid. The OwaMaxConcurrency parameter has a valid range from 0 through 2147483647 inclusive. The default value is 5. To indicate that the number of concurrent connections should be unthrottled (no limit), this value should be set to $null.
+### NOTE: Setting this value to a High Number or $null is not recommended and may affect server performace.
 
 ```yaml
 Type: UInt32