Fix getName phase index for the RPTRST output

[daavid00]

While testing BG and KRG in RPTRST for a GASWATER deck, then this issue came out (e.g., KRG would write the WATKR). This commit fixes this.

[daavid00]

jenkins build this please

[akva2]

I don't understand how this fixes anything. The phases run over an array that is

(gasPhaseIdx, waterPhaseIdx, oilPhaseIdx), 

which is (0,1,2). This does the same, just with a non-named index ?

[daavid00]

When writing for all phases then no problem, but when we only would like to write for one phase like described in the first comment, then the issue appears, gasPhaseIdx would be 1 that results in phaseName to be "WAT" (to reproduce this then you can try to run this with RPTRST 'BASIC=2' KRG /)

[akva2]

right. that was stupid. better fix in #6134

[daavid00]

Thanks, then I am closing this.