provide proper OTA_URL for tasmota32solo1

[barbudor]

Description:

@Jason2866 This allows detection of CORE32SOLO1 build in my_user_config

~/Documents/_perso/repos/Tasmota/build_output/firmware$ strings -f *.bin | grep "ota.tasmota.com"
tasmota32.bin: http://ota.tasmota.com/tasmota32/release/tasmota32.bin
tasmota32solo1.bin: http://ota.tasmota.com/tasmota32/release/tasmota32solo1.bin

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.2.0.2
• I accept the CLA.

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