fix(Tracking): add null check

mastodon/src/main/java/org/joinmastodon/android/utils/Tracking.java

@@ -4,6 +4,7 @@ import android.net.Uri;
 import android.util.Patterns;
 
 import androidx.annotation.NonNull;
+
 import java.util.Arrays;
 import java.util.regex.Matcher;
 
@@ -63,6 +64,8 @@ public class Tracking{
 	@NonNull
 	public static String removeTrackingParameters(@NonNull String url){
 		Uri uri=Uri.parse(url);
+		if(uri==null)
+			return url;
 		Uri.Builder uriBuilder=uri.buildUpon().clearQuery();
 
 		// Iterate over existing parameters and add them back if they are not tracking parameters