When we call mergeRuntimeConfig, the global RuntimeConfig gets
overwritten with the result of the merging, thus affecting the
subsequent delegates.
Do not modify the global RuntimeConfig and instead make a copy
when merging it.
Also, if a value has been provided for CNIDeviceInfoFile in the
delegate's runtimeconfig, overwrite it to avoid possible name
colissions.
Signed-off-by: Adrian Moreno <amorenoz@redhat.com>
