correct the default JQ_COLORS to use 37, not undefined color 39

[DavidBiesack]

No description provided.

[coveralls]

Coverage decreased (-0.03%) to 84.505% when pulling d43abe4 on DavidBiesack:master into e74eab8 on stedolan:master.

[nicowilliams]

Huh, you're quite right that 39 is not a valid color for vt100, but that is what's used in the source, so correcting the manual is not enough!

$ git grep 0\;39
docs/content/manual/manual.yml:      `"JQ_COLORS=1;30:0;39:0;39:0;39:0;32:1;39:1;39"`.
docs/content/manual/v1.6/manual.yml:      `"JQ_COLORS=1;30:0;39:0;39:0;39:0;32:1;39:1;39"`.
jq.1.prebuilt:The default color scheme is the same as setting \fB"JQ_COLORS=1;30:0;39:0;39:0;39:0;32:1;39:1;39"\fR\.
src/jv_print.c:  {COL("1;30"),    COL("0;39"),      COL("0;39"),     COL("0;39"),

[nicowilliams]

Thanks!