Update icons.css

[dlloyd09]

seal_b, seal_d, and seal_e render out of order whenever they appear on ArkhamDB (an outstanding example of this is https://arkhamdb.com/card/08662). In addition, the definition of seal_b contained a stray = that also causes improper rendering; see also that same above-linked card.

Please feel free to edit this as needed; this is only what I think is the correct fix.