Fix issue that the logging content cannot be recoganized in Chinese environment.

Author: Edward Meng

src/Exceptionless/Logging/FileExceptionlessLog.cs

@@ -40,10 +40,10 @@ protected virtual void Init() {
         protected virtual WrappedDisposable<StreamWriter> GetWriter(bool append = false) {
 #if NETSTANDARD
             return new WrappedDisposable<StreamWriter>(new StreamWriter(
-                new FileStream(FilePath, append ? FileMode.Append : FileMode.Truncate, FileAccess.Write, FileShare.ReadWrite), Encoding.ASCII)
+                new FileStream(FilePath, append ? FileMode.Append : FileMode.Truncate, FileAccess.Write, FileShare.ReadWrite), Encoding.UTF8)
             );
 #else
-            return new WrappedDisposable<StreamWriter>(new StreamWriter(FilePath, append, Encoding.ASCII));
+            return new WrappedDisposable<StreamWriter>(new StreamWriter(FilePath, append, Encoding.UTF8));
 #endif
         }