test/misc: empty/folding tests have only one CSeq
test/rfc4475: 3.3.8, 3.3.9 - test the right thing
Revert "undo bbf2f6b7a5d5f37b2e0c5ef0d31b6ee58442631d"

This reverts commit 88ba8ddc1f56d5d2c9666d7ad28d7717c5850ea9.

Conflicts:
	src/sippers.js
Pass test/rfc4475 3.3.8, 3.3.9

see d41926bd7cfcb14515b9601a0b479528aa9a1ba4