Rename tasmota4MB to tasmota-4MB

[Jason2866]

Description:

to fix auto OTA update with minimal variant.
Thx @sfromis for pointing too

Checklist:

• The pull request is done against the latest development branch
• Only relevant files were touched
• Only one feature/fix was added per PR and the code change compiles without warnings
• The code change is tested and works with Tasmota core ESP8266 V.2.7.4.9
• The code change is tested and works with Tasmota core ESP32 V.2.0.6
• I accept the CLA.

NOTE: The code change must pass CI tests. Your PR cannot be merged unless tests pass

[sfromis]

Now, I could do plain OTA upgrade to tasmota-4M.bin.gz via tasmota-minimal.bin.gz, as long as I use my own OTA server supporting that. Not yet from ota.tasmota.com, as the old name is still used there, and obviously not directly from https (my own server proxies that).

[Jason2866]

@arendst can you have a look? Seems it needs changes in your upload script to the OTA server.

[arendst]

Indeed. Will change tomorrow.

[nikito7]

My little hack

[sfromis]

With the renaming to tasmota-4M, workarounds like tasmota4M-minimal are no longer needed, and not done on the OTA server anyway.