Re-enable debuginfo generation.

So what's happened here is this:
- we planned on not having the grubby binary in this package at all
  anymore
- when we did test builds like that, find-debuginfo.sh broke
- since it was completely inconsequential, we disabled building
  debuginfo
- then we re-thought the package layout, and decided to build that
  binary anyway, but forgot to turn debuginfo back on
- also we build the binary as -fPIE, which file(1) says is a "shared
  object"
- brp-strip does not act on shared objects, so it didn't strip

As a result, rpmdiff noticed our binary was not stripped.

This patch re-enables debuginfo, which will cause our binary to get
stripped, as well as to have the correct debuginfo packages in the
output.

Related: rhbz#1619344
Signed-off-by: Peter Jones <pjones@redhat.com>

grubby.spec

@@ -39,8 +39,6 @@ This package provides a grubby compatibility script that manages
 BootLoaderSpec files and is meant to only be used for legacy compatibility
 users with existing grubby users.
 
-%global debug_package %{nil}
-
 %prep
 %setup -q -n grubby-%{version}-1