options_table: fix colorspace minimum option value

The min value for colorspace should be zero and not one since the first
valid index into the frame colorspace array is AVCOL_SPC_RGB which is 0.

libavcodec/options_table.h

@@ -416,7 +416,7 @@ static const AVOption avcodec_options[] = {
 {"iec61966_2_1", "IEC 61966-2-1",    0, AV_OPT_TYPE_CONST, {.i64 = AVCOL_TRC_IEC61966_2_1 }, INT_MIN, INT_MAX, V|E|D, "color_trc_type"},
 {"bt2020_10bit", "BT.2020 - 10 bit", 0, AV_OPT_TYPE_CONST, {.i64 = AVCOL_TRC_BT2020_10 },    INT_MIN, INT_MAX, V|E|D, "color_trc_type"},
 {"bt2020_12bit", "BT.2020 - 12 bit", 0, AV_OPT_TYPE_CONST, {.i64 = AVCOL_TRC_BT2020_12 },    INT_MIN, INT_MAX, V|E|D, "color_trc_type"},
-{"colorspace", "color space", OFFSET(colorspace), AV_OPT_TYPE_INT, {.i64 = AVCOL_SPC_UNSPECIFIED }, 1, AVCOL_SPC_NB-1, V|E|D, "colorspace_type"},
+{"colorspace", "color space", OFFSET(colorspace), AV_OPT_TYPE_INT, {.i64 = AVCOL_SPC_UNSPECIFIED }, 0, AVCOL_SPC_NB-1, V|E|D, "colorspace_type"},
 {"rgb",         "RGB",         0, AV_OPT_TYPE_CONST, {.i64 = AVCOL_SPC_RGB },         INT_MIN, INT_MAX, V|E|D, "colorspace_type"},
 {"bt709",       "BT.709",      0, AV_OPT_TYPE_CONST, {.i64 = AVCOL_SPC_BT709 },       INT_MIN, INT_MAX, V|E|D, "colorspace_type"},
 {"unspecified", "Unspecified", 0, AV_OPT_TYPE_CONST, {.i64 = AVCOL_SPC_UNSPECIFIED }, INT_MIN, INT_MAX, V|E|D, "colorspace_type"},