verify: reference the correct linkrev when a filelog is missing
when a filelog is missing, the first bad revision is the first revision
where the filelog is referenced, not 0.
adding a
diff -r 107ba6f817b5 -r 310ce7989cdc a
--- a/a Thu Jan 01 00:00:01 1970 +0000
+++ b/a Thu Jan 01 00:00:02 1970 +0000
@@ -1,2 +1,3 @@
confuse str.splitlines
embedded
newline
+clean diff