Update casacore to version 3.4.0 / rev 4 via SR 974246
    
    https://build.opensuse.org/request/show/974246
    by user badshah400 + dimstar_suse
    - Add casacore-link-math.patch: Explicitly link to math library when building mirlab [gh#casacore/casacore#1190].
    - Drop ExcludeArch: %ix86 to allow building for related 32-bit systems in light of previous commit.
    - Add an rpmlintrc for shlib-policy-name-error
    - Add upstream patch to fix build on 32-bit architectures: 1129.patch