Rename "nsec3-delegation" to "nsec3_delegation"

The "nsec3-delegation" test was added in a release branch, before commit
67aca1f8c6f19de11f238a402604697be4ff64dc introduced the current system
test naming convention.  Rename the test to comply with that convention.

diff --git a/bin/tests/system/nsec3-delegation/ns1/named.conf.j2 b/bin/tests/system/nsec3_delegation/ns1/named.conf.j2
similarity index 100%
rename from bin/tests/system/nsec3-delegation/ns1/named.conf.j2
rename to bin/tests/system/nsec3_delegation/ns1/named.conf.j2

diff --git a/bin/tests/system/nsec3-delegation/ns1/root.db b/bin/tests/system/nsec3_delegation/ns1/root.db
similarity index 100%
rename from bin/tests/system/nsec3-delegation/ns1/root.db
rename to bin/tests/system/nsec3_delegation/ns1/root.db

diff --git a/bin/tests/system/nsec3-delegation/ns2/iter-too-many.db.j2.manual b/bin/tests/system/nsec3_delegation/ns2/iter-too-many.db.j2.manual
similarity index 100%
rename from bin/tests/system/nsec3-delegation/ns2/iter-too-many.db.j2.manual
rename to bin/tests/system/nsec3_delegation/ns2/iter-too-many.db.j2.manual

diff --git a/bin/tests/system/nsec3-delegation/ns2/named.conf.j2 b/bin/tests/system/nsec3_delegation/ns2/named.conf.j2
similarity index 100%
rename from bin/tests/system/nsec3-delegation/ns2/named.conf.j2
rename to bin/tests/system/nsec3_delegation/ns2/named.conf.j2

diff --git a/bin/tests/system/nsec3-delegation/ns2/sub.iter-too-many.db b/bin/tests/system/nsec3_delegation/ns2/sub.iter-too-many.db
similarity index 100%
rename from bin/tests/system/nsec3-delegation/ns2/sub.iter-too-many.db
rename to bin/tests/system/nsec3_delegation/ns2/sub.iter-too-many.db

diff --git a/bin/tests/system/nsec3-delegation/ns3/named.conf.j2 b/bin/tests/system/nsec3_delegation/ns3/named.conf.j2
similarity index 100%
rename from bin/tests/system/nsec3-delegation/ns3/named.conf.j2
rename to bin/tests/system/nsec3_delegation/ns3/named.conf.j2

diff --git a/bin/tests/system/nsec3-delegation/ns3/trusted.conf.j2 b/bin/tests/system/nsec3_delegation/ns3/trusted.conf.j2
similarity index 100%
rename from bin/tests/system/nsec3-delegation/ns3/trusted.conf.j2
rename to bin/tests/system/nsec3_delegation/ns3/trusted.conf.j2

diff --git a/bin/tests/system/nsec3-delegation/tests_excessive_nsec3_iterations.py b/bin/tests/system/nsec3_delegation/tests_excessive_nsec3_iterations.py
similarity index 100%
rename from bin/tests/system/nsec3-delegation/tests_excessive_nsec3_iterations.py
rename to bin/tests/system/nsec3_delegation/tests_excessive_nsec3_iterations.py