coverage: fix cluacov rockspec URI #3974

Job	Run time
run-perf-tests-ce (1.10, 1.0.0, 2.8.0)	34m 23s
run-perf-tests-ce (2.11, 1.0.0, 2.8.0)	34m 8s
run-tests-ce (1.10.6, 2.8.0)	11m 10s
run-perf-tests-ce (3.0.0, 0.1.25)	40m 0s
run-tests-ce (1.10, 2.8.0)	8m 8s
run-tests-ce (2.8, 2.8.0)	10m 23s
run-tests-ce (2.10, 2.8.0)	9m 39s
run-tests-ee (1.10, tarantool-enterprise-sdk-1.10.15-0-r609, 2.8.0)	8m 0s
run-tests-ce (2.11, 2.8.0)	7m 53s
run-tests-ee (1.10, tarantool-enterprise-sdk-1.10.15-0-r609, 1.0.0, 2.8.0)	7m 25s
run-tests-ce (1.10, 1.0.0, 2.8.0)	10m 8s
run-tests-ee (2.11, tarantool-enterprise-sdk-nogc64-2.11.2-0-r609.linux.x86_64, 2.8.0)	8m 8s
run-tests-ce (2.7, 2.8.0)	11m 32s
run-tests-ee (2.11, tarantool-enterprise-sdk-nogc64-2.11.2-0-r609.linux.x86_64, 1.0.0, 2.8.0)	7m 52s
run-tests-ce (2.10, 0.10.0, 2.7.9)	7m 46s
run-tests-ee (3.0, tarantool-enterprise-sdk-gc64-3.0.0-0-gf58f7d82a-r23.linux.x86_64, 0.1.25)	9m 4s
run-tests-ce (2.11, 1.0.0, 2.8.0, true)	12m 25s
run-tests-ce (2.11, 1.0.0, 0.1.25)	3m 12s
run-tests-ce (3.0.0, 0.1.25)	14m 15s
run-tests-ce (master, 0.1.26)	20m 4s
	4h 35m 35s

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