git: ignore re-formatting commit v9.1.0879 for blame

Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/.git-blame-ignore-revs b/.git-blame-ignore-revs
index 5888c31..cb635a2 100644
--- a/.git-blame-ignore-revs
+++ b/.git-blame-ignore-revs
@@ -8,3 +8,5 @@
 
 # Patch v9.1.0829 expanded tabs to spaces in sound.c
 8ce738de3fd7192fa6274730594305cde780074c
+# Patch v9.1.0879 reformated sound.c and sign.c
+3cf094edaff815141d9941b8dba52b9e77d8dfc1