fix(ios): correctly append exif on iOS 14 (#685)

diff --git a/src/ios/CDVCamera.m b/src/ios/CDVCamera.m
index 0d6e7e5..2f2738b 100644
--- a/src/ios/CDVCamera.m
+++ b/src/ios/CDVCamera.m
@@ -651,13 +651,15 @@
     CDVPluginResult* result = nil;
 
     if (self.metadata) {
-        CGImageSourceRef sourceImage = CGImageSourceCreateWithData((__bridge CFDataRef)self.data, NULL);
+        NSData* dataCopy = [self.data mutableCopy];
+        CGImageSourceRef sourceImage = CGImageSourceCreateWithData((__bridge CFDataRef)dataCopy, NULL);
         CFStringRef sourceType = CGImageSourceGetType(sourceImage);
 
         CGImageDestinationRef destinationImage = CGImageDestinationCreateWithData((__bridge CFMutableDataRef)self.data, sourceType, 1, NULL);
         CGImageDestinationAddImageFromSource(destinationImage, sourceImage, 0, (__bridge CFDictionaryRef)self.metadata);
         CGImageDestinationFinalize(destinationImage);
 
+        dataCopy = nil;
         CFRelease(sourceImage);
         CFRelease(destinationImage);
     }