py3: fix absorb -i

Summary: The command does not crash but `-` lines are ignored.

Reviewed By: DurhamG

Differential Revision: D23357655

fbshipit-source-id: f48568bc193f947503bc19f3e192b33346c317e1

Author: quark-zju

eden/scm/edenscm/hgext/absorb/__init__.py

@@ -879,7 +879,7 @@ def _parsechunk(hunk):
     patchlines = mdiff.splitnewlines(buf.getvalue())
     # hunk.prettystr() will update hunk.removed
     a2 = a1 + hunk.removed
-    blines = [l[1:] for l in patchlines[1:] if l[0] != "-"]
+    blines = [l[1:] for l in patchlines[1:] if l[0] != b"-"]
     return path, (a1, a2, blines)