Add full LG4 (VS986) support

Add productId to the Wireshark dissector and udev rule, adjust the
serial path detection logic to find the right key
(`\Device\LGVZANDNETDIAG1`). Now you do not need to pass `--serial COM4`
anymore.

Reportedly fails in VirtualBox with USB passthrough, but works fine on
Linux. Thanks @invisiblek for testing!

lglaf.lua

@@ -97,4 +97,5 @@ function lglaf.init()
     local usb_product = DissectorTable.get("usb.product");
     usb_product:add(0x1004633e, lglaf) -- LG G3 D855
     usb_product:add(0x1004627f, lglaf) -- LG G3 VS985
+    usb_product:add(0x10046298, lglaf) -- LG G4 VS986
 end

lglaf.py

@@ -275,16 +275,21 @@ def detect_serial_path():
     try:
         path = r'HARDWARE\DEVICEMAP\SERIALCOMM'
         with winreg.OpenKey(winreg.HKEY_LOCAL_MACHINE, path) as key:
-            return winreg.QueryValueEx(key, r'\Device\LGANDNETDIAG1')[0]
-    except OSError:
-        return None
+            for i in range(winreg.QueryInfoKey(key)[1]):
+                name, value, value_type = winreg.EnumValue(key, i)
+                # match both \Device\LGANDNETDIAG1 and \Device\LGVZANDNETDIAG1
+                name = name.upper()
+                if name.startswith(r'\DEVICE\LG') and name.endswith('ANDNETDIAG1'):
+                    return value
+    except OSError: pass
+    return None
 
 def autodetect_device():
     if winreg is not None and 'usb.core' not in sys.modules:
         serial_path = detect_serial_path()
         _logger.debug("Using serial port: %s", serial_path)
         if not serial_path:
-            raise RuntimeError("Please install LG drivers or PyUSB")
+            raise RuntimeError("Device not found, try installing LG drivers")
         return FileCommunication(serial_path)
     else:
         if 'usb.core' not in sys.modules:

rules.d/42-usb-lglaf.rules

@@ -3,3 +3,5 @@
 SUBSYSTEM=="usb", ATTRS{idVendor}=="1004", ATTRS{idProduct}=="633e", TAG+="uaccess"
 # LG G3 (VS985) in download mode
 SUBSYSTEM=="usb", ATTRS{idVendor}=="1004", ATTRS{idProduct}=="627f", TAG+="uaccess"
+# LG G4 (VS986) in download mode
+SUBSYSTEM=="usb", ATTRS{idVendor}=="1004", ATTRS{idProduct}=="6298", TAG+="uaccess"