git: Disable rerere

I had this change sitting around so long that I forgot why exactly I
disabled it, but know that some problem arose from rerere. I think that
even though it is super cool, it brings a sneaky new layer of possible
errors. Maybe I'll re-enable it in the future.

.config/git/config

@@ -114,7 +114,7 @@
 [rebase]
 	autostash = true
 [rerere]
-	enabled = true
+	enabled = false
 [status]
 	submodulesummary = true
 [submodule]