Ticket 49937 - Log buffer exceeded emergency logging msg is not thread-safe
    
    Bug Description:  Multiple operations making modificatiosn on a DN
                      that is very large can crash the server, because
                      when we do emergency logging, we close and reopen
                      the errors log withgout hold the error log write
                      lock.  This causes the FD pointer to be become
                      invalid and triggers a crash.
    
    Fix description:  Hold the errors log write lock while closing and
                      reopening the log
    
    https://pagure.io/389-ds-base/issue/49937
    
    Reviewed by: vashirov(Thanks!)
    
    (cherry picked from commit 8ff8cb850be8a93f75aa3007ee2131c026f4962b)