"-z 9" size regression from WebP 1.2.2

[MasterInQuestion]

    "1_1.2.2.webp": 141,316 B
    "1_1.4.0.webp": 141,506 B

    "2_1.2.2.webp": 96,174 B
    "2_1.4.0.webp": 96,302 B

    ~ 0.13% bloat.

[MasterInQuestion]

    Further example for the demo:
    "diff_quot.0_1.2.2.webp": 71,864 B
    "diff_quot.0_1.4.0.webp": 71,994 B (~ +0.181%)
    "diff_quot.1_1.2.2.webp": 72,084 B
    "diff_quot.1_1.4.0.webp": 72,092 B (~ +0.011%)
    .
    "diff_quot.webp" (1.4.0): 133,580 B (~ -0.291%)
    "diff_quot_1.2.2.webp": 133,970 B