Be more lenient when loading gpl palettes

Apparently, non-conforming gpl files exist:

https://lospec.com/palette-list/endesga-16

GIMP Palette
228 166 114 #e4a672
184 111 80 #b86f50
116 63 57 #743f39
63 40 50 #3f2832
158 40 53 #9e2835
229 59 68 #e53b44
251 146 43 #fb922b
255 231 98 #ffe762
99 198 77 #63c64d
50 115 69 #327345
25 61 63 #193d3f
79 103 129 #4f6781
175 191 210 #afbfd2
255 255 255 #ffffff
44 232 244 #2ce8f4
4 132 209 #0484d1