Ticket 49177 - rpm would not create valid pkgconfig files
    
    Bug Description:  pkgconfig from the rpm was not valid.
    
    Fix Description:  Add missing variables with directories
    to dirsrv.pc. Otherwise pkgconfig cannot expand variables
    ${libdir}, ${includedir}
    
    https://pagure.io/389-ds-base/issue/49177
    
    Author: lslebodn
    
    Review by: mreynolds
    
    Signed-off-by: Mark Reynolds <mreynolds@redhat.com>