Incorrect contexted string extracted from windows RC files

[Hleb Valoshka]

in celestia.rc, line 658 we have:

AUTOCHECKBOX    NC_("plural", "Spacecraft"), IDC_LABELSPACECRAFT, 60, 108, 59, 10, 0, WS_EX_LEFT

this should be extracted as a line with context, instead we have "plural" extracted as msgid