[buildbot] phase1: dlprune: fix cannot delete ‘dl/’: Not a directory

[LEDE Commits]

ynezz pushed a commit to buildbot.git, branch master:
https://git.openwrt.org/280a07b9e6ba928ce5495dc19ed68d17e990396c

commit 280a07b9e6ba928ce5495dc19ed68d17e990396c
Author: Petr Štetiar <ynezz at true.cz>
AuthorDate: Thu Jun 1 07:56:49 2023 +0200

    phase1: dlprune: fix cannot delete ‘dl/’: Not a directory
    
    dlprune currently fails with following error:
    
     find: cannot delete ‘dl/’: Not a directory
    
    Initial idea was to delete only stuff under download directory and not
    the download directory itself, so lets adjust the find command
    accordingly.
    
    Fixes: 68b20ed67b5e ("phase1: prune unused files from dl/")
    Signed-off-by: Petr Štetiar <ynezz at true.cz>
---
 phase1/master.cfg | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/phase1/master.cfg b/phase1/master.cfg
index 4fb28b6..91755cd 100644
--- a/phase1/master.cfg
+++ b/phase1/master.cfg
@@ -881,7 +881,7 @@ for target in targets:
 		name = "dlprune",
 		description = "Pruning dl/",
 		descriptionDone = "dl/ pruned",
-		command = 'find dl/ -atime +15 -delete -print',
+		command = 'find dl/ -mindepth 1 -atime +15 -delete -print',
 		logEnviron = False,
 	))