test: increase process termination waiting timeout

This commit increases a time to wait of the process termination. It may
take longer than 5 seconds, when tarantool is built with an address
sanitizer. The address sanitizer generates a report at the process
termination and it is not always a fast thing.

NO_DOC=test fix
NO_CHANGELOG=see NO_DOC

(cherry picked from commit 5260bc2a)