set jpeg image compression to 85%

deltachat-ios/Controller/ChatViewController.swift

@@ -883,7 +883,7 @@ extension ChatViewController: MessagesDataSource {
     private func sendImage(_ image: UIImage, message: String? = nil) {
         DispatchQueue.global().async {
             if let compressedImage = image.dcCompress() {
-                // at this point image is compressed by 50% by default
+                // at this point image is compressed by 85% by default
                 let pixelSize = compressedImage.imageSizeInPixel()
                 let path = Utils.saveImage(image: compressedImage)
                 let msg = DcMsg(viewType: DC_MSG_IMAGE)

deltachat-ios/Extensions/UIImage+Extension.swift

@@ -85,7 +85,7 @@ extension UIImage {
 
         let imageData = self.isTransparent() ?
             img?.pngData() :
-            img?.jpegData(compressionQuality: 0.5)
+            img?.jpegData(compressionQuality: 0.85)
 
         UIGraphicsEndImageContext()
         return UIImage(data: imageData!)