Rebuild the Carthage project with Swift 5 for gRPC-Core 1.23. (#613)

* Rebuild the Carthage project with Swift 5 for gRPC-Core 1.23.

* Rebuild the Carthage project with Swift 4.2.

SwiftGRPC-Carthage.xcodeproj/GeneratedModuleMap/CNIONghttp2/module.modulemap

@@ -1,4 +1,4 @@
 module CNIONghttp2 {
-    umbrella "/Users/tair/projects/grpc-swift/.build/checkouts/swift-nio-http2/Sources/CNIONghttp2/include"
+    umbrella "/Users/daniel/Documents/Xcode/Mac/grpc-swift/.build/checkouts/swift-nio-http2.git-410920432295335354/Sources/CNIONghttp2/include"
     export *
 }