[buildbot] phase1: populateTargets: log branch name as well

[LEDE Commits]

ynezz pushed a commit to buildbot.git, annotated tag v8:
https://git.openwrt.org/e332f694130d40913083e52f454f7851b85000ac

commit e332f694130d40913083e52f454f7851b85000ac
Author: Petr Štetiar <ynezz at true.cz>
AuthorDate: Sun Jun 18 07:28:01 2023 +0200

    phase1: populateTargets: log branch name as well
    
    So the progress is more verbose.
    
    Signed-off-by: Petr Štetiar <ynezz at true.cz>
---
 phase1/master.cfg | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/phase1/master.cfg b/phase1/master.cfg
index c4bccea..d443811 100644
--- a/phase1/master.cfg
+++ b/phase1/master.cfg
@@ -297,9 +297,10 @@ def populateTargets():
     targets that only exist in specific branches get built.
     This takes a while during master startup but is executed only once.
     """
-    log.msg("Populating targets, this will take time")
     sourcegit = work_dir + "/source.git"
     for branch in branchNames:
+        log.msg(f"Populating targets for {branch}, this will take time")
+
         if os.path.isdir(sourcegit):
             subprocess.call(["rm", "-rf", sourcegit])