Avoid repetitive initialization.

scripts/config.py

@@ -7,12 +7,12 @@
 # under the terms of GNU General Public License, v.2 or above
 
 iso_link = ""
-usb_disk = ""
+usb_disk = None
 usb_mount = ""
 usb_uuid = ""
 usb_label = ""
 usb_details = ''
-image_path = ""
+image_path = None
 persistence = 0
 persistence_available = False
 persistence_max_size = 0

scripts/mbusb_gui.py

@@ -57,9 +57,6 @@ class AppGui(qemu.Qemu, Imager, QtWidgets.QMainWindow, Ui_MainWindow):
 		self.ui.label_persistence.setVisible(False)
 		self.ui.slider_persistence.setVisible(False)
 
-		config.usb_disk = None
-		config.image_path = None
-
 		#  Main Tab
 		self.ui.checkbox_all_drives.clicked.connect(self.onAllDrivesClicked)
 		self.ui.button_detect_drives.clicked.connect(self.onRefreshClick)