Checkmk Werk 12715: oracle_performance: could crash with KeyError (Shared IO Pool Size)

ID: 12715 Title: oracle_performance: could crash with KeyError (Shared IO Pool Size) Component: Checks & agents Level: 1 Class: Bug fix Version: 2.1.0i1 In case the `Shared IO Pool Size` was not provided by the `oracle_performance` section the check would crash with a KeyError. This change just checks for the existence of `Shared IO Pool Size` prior to accessing it.