Master channel program change error

[riban-bw]

Describe the bug The first time a program change is sent to master channel there is an error in the log: 'No such file or directory: '/zynthian/zynthian-my-data/snapshots/Last State'

To Reproduce Steps to reproduce the behaviour:

1. Start Zynthian from cold
2. Enable master channel
3. Send MIDI program change message on master channel

Expected behaviour No error

Setup:

• HARDWARE Raspberry Pi 4 Model B Rev 1.4 Audio: ZynADAC Display: ZynScreen 3.5 (v1) Wiring: MCP23017_ZynScreen I2C: MCP23017@0x20, MCP23008@0x21, ADS1115@0x48, MCP4728@0x60
• SYSTEM Raspbian GNU/Linux 10 (buster) Build Date: 2020-09-05 Memory: 6% (126M/1872M) SD Card: 70% (19G/29G) Temperature: 61.8ºC Overclock: Medium USB Storage: 5% (9.7G/235G)
• MIDI Profile: default.sh Tuning: 440 Hz Receive Mode: Stage (Omni On) ZS3 Sub-SnapShots: On MIDI to Output: On Master Channel: 16
• SOFTWARE zyncoder: testing (6eb5496) zynthian-ui: testing (68c0485) zynthian-sys: testing (af606bf) zynthian-data: testing (45b44f9) zynthian-webconf: testing (706d78d)

Additional context This occurs in stable 2109 and current testing, i.e. an historical issue.

[riban-bw]

zynthian_gui_snapshot: midi_program_change self.bank_dir=self.list_data[0][2] is setting bank to "Last Saved" which is plainly wrong. I wonder if it was supposed to be self.bank_dir=self.list_data[2][0]