CUST-4527 added 'unknown' as a conferecing provider

Author: samuelpx

src/main/kotlin/com/nylas/models/ConferencingProvider.kt

@@ -23,7 +23,7 @@ enum class ConferencingProvider {
 
   @Json(name = "skypeForConsumer")
   SKYPE_FOR_CONSUMER,
- 
+
   @Json(name = "unknown")
   UNKNOWN,
 }