HASPmota error when page '1' is not defined

[s-hadinger]

Description:

Fix malfunction when there is no page with "id"=1 defined. Now the page with the lowest page id is the main page.

Renamed oh to hm and _oh to _hm (from OpenHASP to HASPmota)

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.2.7.8
• The code change is tested and works with Tasmota core ESP32 V.3.1.0.240926
• I accept the CLA.

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