OpenSSL error: error:0906D06C:PEM routines:PEM_read_bio:no start line

[iobiz01]

Steps to reproduce

1. Upgrade phpMyAdmin to 4.6.6
2. Login
3. See error after login and logout, error: OpenSSL error: error:0906D06C:PEM routines:PEM_read_bio:no start line

Expected behaviour

No error should occur in the login/logout page

Actual behaviour

I see error after login and logout: OpenSSL error: error:0906D06C:PEM routines:PEM_read_bio:no start line

Server configuration

Operating system:
CentOS 6.8 X64
Web server:
Apache 2.2.15
Database:
mySQL 5.6.35
PHP version:
5.6.30
phpMyAdmin version:
4.6.6
OpenSSL version:
1.0.1e-fips 11 Feb 2013

Client configuration

Browser:
Firefox 51.0
Operating system:
OSX 10

[nijel]

See #12924