Temporary workaround for Kitura/Kitura#1034 (#211)

* Kitura/Kitura#1034: Debugging second crash, sacrificial first field in IncomingSocketHandler

The crash always seems to relate to the first instance field of the IncomingSocketHandler class. Introducing a dummy one that is never used apparently avoids the crash.

* Add comment

Sources/KituraNet/IncomingSocketHandler.swift

@@ -35,7 +35,12 @@ import Socket
 public class IncomingSocketHandler {
 
  static let socketWriterQueue = DispatchQueue(label: "Socket Writer")
-
+
+ // This variable is unused. It is a temporary workaround for a rare crash under load
+ // (see: https://github.com/IBM-Swift/Kitura/issues/1034) while a proper fix is
+ // investigated.
+ var superfluousOptional:String? = String(repeating: "x", count: 2)
+
  #if os(OSX) || os(iOS) || os(tvOS) || os(watchOS) || GCD_ASYNCH
  static let socketReaderQueues = [DispatchQueue(label: "Socket Reader A"), DispatchQueue(label: "Socket Reader B")]