None of the configuration above worked for me on my CentOS 7 server. After hours of searching, that's what worked for me:
Edit file phpMyAdmin.conf
sudo nano /etc/httpd/conf.d/phpMyAdmin.conf
And replace this at the top:
<Directory /usr/share/phpMyAdmin/>
AddDefaultCharset UTF-8
<IfModule mod_authz_core.c>
# Apache 2.4
<RequireAny>
#Require ip 127.0.0.1
#Require ip ::1
Require all granted
</RequireAny>
</IfModule>
<IfModule !mod_authz_core.c>
# Apache 2.2
Order Deny,Allow
Deny from All
Allow from 127.0.0.1
Allow from ::1
</IfModule>
</Directory>