corrected upload fix to macOS 10.15.4

Author: donnywals

Sources/TUSKit/Files.swift

@@ -157,7 +157,7 @@ final class Files {
         }
     }
 
-    @available(iOS 13.4, macOS 10.15, *)
+    @available(iOS 13.4, macOS 10.15.4, *)
     func streamingData(_ dataGenerator: () -> Data?, id: UUID, preferredFileExtension: String? = nil) throws -> URL {
         try queue.sync {
             try makeDirectoryIfNeeded()

Sources/TUSKit/Tasks/UploadDataTask.swift

@@ -182,7 +182,7 @@ final class UploadDataTask: NSObject, IdentifiableTask {
 
         // Can't use switch with #available :'(
         let data: Data
-        if let range = self.range, #available(iOS 13.4, macOS 10.15, *) { // Has range, for newer versions
+        if let range = self.range, #available(iOS 13.4, macOS 10.15.4, *) { // Has range, for newer versions
             var offset = range.startIndex
 
             return try files.streamingData({