`vips` is unable to output thumbnails if the input file has an invalid ICC profile.
### Known affected files
* https://commons.wikimedia.org/wiki/File:Julia_Margaret_Cameron_-_Queen_of_the_May_-_1984.166_-_Cleveland_Museum_of_Art.tif `profile 'icc': 0h: PCS illuminant is not D50`
* https://commons.wikimedia.org/wiki/File:The_Rames%C3%AAum._The_remains_of_the_great_hypostyle_of_the_Temple_of_Rameses_II._The_figures_of_Christian_slaves_have_been_painted_on_some_of_the_columns_(NYPL_b10607452-80839).tiff `profile 'icc': 0h: PCS illuminant is not D50`
* https://commons.wikimedia.org/wiki/File:Special_Collections_University_of_Amsterdam_-_Iconographia_Zoologica_-_UBA01_IZ1207714_001_-_Gubernatrix_cristata_Vieillot,_1817_-_P._Oudart_-_G._Engelmann_-_Print_-_1825-1834.tif `profile 'icc': 0h: PCS illuminant is not D50`
* https://commons.wikimedia.org/wiki/File:Moivre_-_Doctrine_of_chances,_1761_-_722666.tif `profile 'icc': 'desc': ICC profile tag start not a multiple of 4`
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https://upload.wikimedia.org/wikipedia/commons/thumb/2/28/Julia_Margaret_Cameron_-_Queen_of_the_May_-_1984.166_-_Cleveland_Museum_of_Art.tif/lossy-page1-364px-Julia_Margaret_Cameron_-_Queen_of_the_May_-_1984.166_-_Cleveland_Museum_of_Art.tif.jpg
Request from x.x.x.x via cp1082 cp1082, Varnish XID 389143731
Error: 429, Too Many Requests at Thu, 28 Mar 2019 22:04:48 GMT
````CommandError: (['/usr/bin/vips', 'shrink', '/srv/thumbor/tmp/thumbor@8818/tmpE_GnDj', '/srv/thumbor/tmp/thumbor@8818/tmpQUoG4w/vips_result.png', '20', '20'], '', 'vipspng: profile \'icc\': 0h: PCS illuminant is not D50\nvips2png: unable to write "/srv/thumbor/tmp/thumbor@8818/tmpQUoG4w/vips_result.png"\n', 1)````