fix t/ttot bug in 46/NDC, correct scenario self-reference in NGFS config

[orichters]

Purpose of this PR

• Parameter definitions must use ttot, not t. Error introduced by myself :/
• With use of NPi and change of order, h_cpol used h_cpol as path_gdx_ref which fails. Fixed that temporarily, will update NGFS config anyway in the future.

Type of change

• Bug fix

Checklist:

• My code follows the coding etiquette
• I performed a self-review of my own code
• I explained my changes within the PR, particularly in hard-to-understand areas
• Automated modeltests would ignore these files anyway. Therefore: ./start.R -t config/scenario_config_NGFS_v4.csv startgroup=* works, as does compiling a scenario using the 46/NDC module