bug#42174: GNU Icecat showing Github Icons?

[Ricardo Wurmus]

I see the same on https://ie.wikipedia.org/wiki/Lewis_Carroll (and other
pages of the ie.wikipedia.org site), but not on other sites.

I have these fonts installed in my profile:

--8<---------------cut here---------------start------------->8---
font-wqy-zenhei 0.9.45  out     
/gnu/store/4666sykl746p9vf4k2vh0nkiw12zjhs5-font-wqy-zenhei-0.9.45
font-tex-gyre   2.005   out     
/gnu/store/pyw1h9gh77b1k8wm26vb9qfbk083qkhf-font-tex-gyre-2.005
font-google-noto        20171025        out     
/gnu/store/g2szydnbvs7qqy2nf7qylba0rapajmd8-font-google-noto-20171025
font-inconsolata        3.000   out     
/gnu/store/8vq65z92r51ghnxbgdss9irk23df9s5f-font-inconsolata-3.000
font-adobe-source-han-sans      1.004   out     
/gnu/store/vravfg76hqm27lrylhc2y44zs1y9zyn2-font-adobe-source-han-sans-1.004
font-awesome    4.7.0   out     
/gnu/store/gknn01i1nr80apmcx42w36cqcz3zzri2-font-awesome-4.7.0
font-google-roboto      2.136   out     
/gnu/store/3mv6bxcvdds1npbg2wf10901xh9y3x03-font-google-roboto-2.136
font-dejavu     2.37    out     
/gnu/store/7y3lvk3xf4im8n44337mc6y0ccysvfia-font-dejavu-2.37
font-adobe75dpi 1.0.3   out     
/gnu/store/gypnv4gfdbp44f9zcg2gsij6qlijm3kd-font-adobe75dpi-1.0.3
font-adobe100dpi        1.0.3   out     
/gnu/store/nhq03m9x7armfdpyj63hq1lqw82vzxzi-font-adobe100dpi-1.0.3
font-liberation 2.1.2   out     
/gnu/store/39j1dcvx5996019dqh9jn8xc0pyg7jb0-font-liberation-2.1.2
font-gnu-unifont        13.0.05 out     
/gnu/store/ajnwk1yfdlf4cjgya1laww497q98sqj7-font-gnu-unifont-13.0.05
font-fira-code  5.2     out     
/gnu/store/k0jya8b6adxymjxpcc2yr4590rwpr1dn-font-fira-code-5.2
--8<---------------cut here---------------end--------------->8---

-- 
Ricardo