Disable I/O in TestStructuredAMRGridConnectivity

This commit disables the I/O in the TestStructuredAMRGridConnectivity.
These files are useful for debugging purposes and are not part of
the test.

Change-Id: Ib845f3a0d96176c78e528a029e7fd0d505cfa542
Merge topic 'fix-testamr-connectivity' into master

8beb89a2 Disable I/O in TestStructuredAMRGridConnectivity