Merge pull request #1938 from nextcloud/wiswedel/eolCleanup18+17+16

updated EOL for MySQL and MariaDB

Author: nickvergessen

admin_manual/installation/system_requirements.rst

@@ -21,7 +21,7 @@ For best performance, stability and functionality we have documented some recomm
 |                  | - openSUSE Leap 42.1+                                                 |
 |                  | - CentOS 8                                                            |
 +------------------+-----------------------------------------------------------------------+
-| Database         | - **MySQL 5.6+ or MariaDB 5.5, 10.1+** (recommended)                  |
+| Database         | - **MySQL 5.7+ or MariaDB 10.2+** (recommended)                       |
 |                  | - Oracle Database 11g (*only as part of an enterprise subscription*)  |
 |                  | - PostgreSQL 9.5/9.6/10/11                                            |
 |                  | - SQLite (*only recommended for testing and minimal-instances*)       |