client: don't delete unrecognized stuff in projects/ #5261

Job	Run time
libs-build	5m 30s
apps-build	8m 49s
libs-cmake-build	7m 4s
client-armv6-build	2m 59s
client-arm-build	3m 39s
client-arm64-build	3m 10s
client-x86-build	3m 21s
client-x86_64-build	3m 22s
manager-build (assembleRelease)	4m 5s
manager-build (assembleXiaomi_release)	4m 4s
manager-build (assembleArmv6_release)	4m 7s
manager-build (jacocoTestReportDebug)	5m 44s
	55m 54s

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