fstest/test_all: set cache backend wait time to 30m to fix integration tests

fstest/test_all/test_all.go

@@ -419,6 +419,9 @@ func main() {
 		}
 	}
 
+	// workaround for cache backend as we run simultaneous tests
+	_ = os.Setenv("RCLONE_CACHE_DB_WAIT_TIME", "30m")
+
 	// start the tests
 	results := make(chan *test, 8)
 	awaiting := 0