Sometimes the connection to the VictronEnergy Device is not possible

[jonashoechst]

As described by @lampep in https://github.com/Nature40/tRackIT-OS/issues/14:

2023-02-20 16:22:10.258601 INFO:smartsolar:Connecting to nearest VEDevice
2023-02-20 16:22:15.821099 INFO:smartsolar:[e7:96:b4:4f:83:43] Discovered VictronEnergy device "E7-96-B4-4F-83-43", RSSI: -51
2023-02-20 16:22:15.848886 INFO:smartsolar:[e7:96:b4:4f:83:43] Selected nearest device "E7-96-B4-4F-83-43"
2023-02-20 16:22:15.855310 INFO:smartsolar:Creating VictronEnergy pairing agent
2023-02-20 16:22:16.366205 ERROR:smartsolar:[e7:96:b4:4f:83:43] Pairing failed, rasing RuntimeError.
2023-02-20 16:22:16.370724 INFO:smartsolar:Querying finished.
2023-02-20 16:22:16.372194 WARNING:mqttutil:Task [smartsolar] failed:
2023-02-20 16:22:16.379578 ERROR:mqttutil:("Pairing VictronEnergy Device '%s' [%s] failed.", dbus.String('E7-96-B4-4F-83-43', variant_level=1), 'e7:96:b4:4f:83:43')
2023-02-20 16:22:16.379578 Traceback (most recent call last):
2023-02-20 16:22:16.379578 File "/home/pi/pymqttutil/mqttutil/main.py", line 131, in run
2023-02-20 16:22:16.379578 result = self._eval()
2023-02-20 16:22:16.379578 File "/home/pi/pymqttutil/mqttutil/main.py", line 80, in _eval
2023-02-20 16:22:16.379578 result = eval(self.func_str)
2023-02-20 16:22:16.379578 File "", line 1, in 
2023-02-20 16:22:16.379578 File "/home/pi/pysmartsolar/smartsolar/init.py", line 423, in read_nearest_vedevice
2023-02-20 16:22:16.379578 d = manager.connect_nearest_vedevice(discovery_duration, passkey=passkey)
2023-02-20 16:22:16.379578 File "/home/pi/pysmartsolar/smartsolar/init.py", line 406, in connect_nearest_vedevice
2023-02-20 16:22:16.379578 raise RuntimeError("Pairing VictronEnergy Device '%s' [%s] failed.", d.alias(), d.mac_address)
2023-02-20 16:22:16.379578 RuntimeError: ("Pairing VictronEnergy Device '%s' [%s] failed.", dbus.String('E7-96-B4-4F-83-43', variant_level=1), 'e7:96:b4:4f:83:43')