added missing alt attribute
added missing alt attribute

https://bugzilla.redhat.com/show_bug.cgi?id=1270700
(transferred from ManageIQ/manageiq@e526d6c99d56b934ba2afe51087f353f911b0558)

ManageIQ/manageiq-ui-classic,ManageIQ/manageiq-ui-classic,ManageIQ/manageiq-ui-classic,ManageIQ/manageiq-ui-classic