fixed persisted scan state on scan cancelling

app/src/main/java/org/foxarmy/barcodescannerforemployees/activities/AddAbstractProductActivity.kt

@@ -307,11 +307,11 @@ class AddAbstractProductActivity : AppCompatActivity() {
             if (result.contents == null) {
                 Toast.makeText(this, getString(R.string.cancelled), Toast.LENGTH_SHORT).show()
             } else {
-                scanningBarcode = false
                 val scannedBarcode = result.contents
                 barcodeText.setText(scannedBarcode)
                 performRequest(scannedBarcode)
             }
+            scanningBarcode = false
         }
     }