[hans@localhost ~]$ sudo prelink /usr/lib64/thunderbird/libprldap60.so
prelink: /usr/lib64/thunderbird/libprldap60.so: Could not find one of the dependencies

ldd gives:

[hans@localhost ~]$ ldd /usr/lib64/thunderbird/libprldap60.so
        linux-vdso.so.1 (0x00007fff343ff000)
        libldap60.so => not found
        libplds4.so => /lib64/libplds4.so (0x00007fa2cb24f000)
        libplc4.so => /lib64/libplc4.so (0x00007fa2cb04b000)
        libnspr4.so => /lib64/libnspr4.so (0x00007fa2cae0f000)
        libpthread.so.0 => /lib64/libpthread.so.0 (0x00007fa2cabf2000)
        libdl.so.2 => /lib64/libdl.so.2 (0x00007fa2ca9ee000)
        libc.so.6 => /lib64/libc.so.6 (0x00007fa2ca639000)
        /lib64/ld-linux-x86-64.so.2 (0x0000003000000000)

Note that libldap60.so is part of thunderbird itself, but as such not in the default ld search path confusing prelink (and ldd).