Fix dev server output #785

Job	Run time
Test Browser on Linux (firefox, default)	1m 23s
Test Browser on Linux (firefox, main)	43s
Test Browser on macOS (safari, default)	2m 2s
Test Browser on macOS (safari, main)	1m 17s
Test Browser on macOS (safari, disabled)	1m 15s
Test Browser on Linux (chrome, default)	1m 9s
Test Build	27s
Test Shell (spidermonkey, main)	49s
Test Browser on Linux (chrome, main)	36s
Test Shell (spidermonkey, disabled)	1m 58s
Test Browser on Linux (firefox, disabled)	1m 24s
Test Shell (jsc, default)	3m 7s
Test Shell (jsc, disabled)	1m 50s
Test Shell (v8, main)	39s
Test Shell (v8, disabled)	1m 31s
Test Browser on Linux (chrome, disabled)	1m 5s
Test Shell (jsc, main)	41s
Test Shell (v8, default)	2m 46s
Test Shell (spidermonkey, default)	5m 12s
	29m 54s

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