Provide template gai.conf in glibc-doc
    
    The gai.conf template used to be shipped via glibc-common, but was
    incorrectly removed during 1fa03e97ae4cb4 ("Introduce new
    glibc-doc.noarch subpackage (#1346925)" as unnecessary.  However, it has
    value as a template file and shipping it is preferable.  This commit
    reinstates the file at /usr/share/doc/glibc/gai.conf as part of the
    glibc-doc subpackage.