fixed Swift5 warnings

Author: alex-kepar

Source/WebSocket.swift

@@ -1509,7 +1509,7 @@ private class InnerWebSocket: Hashable {
             }
         }
         let r = arc4random()
-        var maskBytes : [UInt8] = [UInt8(r >> 0 & 0xFF), UInt8(r >> 8 & 0xFF), UInt8(r >> 16 & 0xFF), UInt8(r >> 24 & 0xFF)]
+        let maskBytes : [UInt8] = [UInt8(r >> 0 & 0xFF), UInt8(r >> 8 & 0xFF), UInt8(r >> 16 & 0xFF), UInt8(r >> 24 & 0xFF)]
         for i in 0 ..< 4 {
             head[hlen] = maskBytes[i]
             hlen += 1

SwiftWebSocket.xcodeproj/project.pbxproj

@@ -352,10 +352,9 @@
 			};
 			buildConfigurationList = 03D1E6FD1B20897100AC49AC /* Build configuration list for PBXProject "SwiftWebSocket" */;
 			compatibilityVersion = "Xcode 3.2";
-			developmentRegion = English;
+			developmentRegion = en;
 			hasScannedForEncodings = 0;
 			knownRegions = (
-				English,
 				en,
 				Base,
 			);