Bug 9049: Don't use shadow with rebuild_zebra -r

Due to a limitation of Zebra, the register must be cleared *before*
doing shadow indexing if you want to reset the indexes. In light of
that, it does not make sense to do shadow indexing at all when
rebuild_zebra.pl is run with the -r switch. This patch makes -r (reset)
imply -n (no shadow).

To test:
1) Run `rebuild_zebra.pl -b -r -v -v -v`
2) Note that the script never runs the merge phase

Without the patch I see log lines refering to the shadow cache (enabling shadow spec=/home/koha/koha-dev/var/lib/zebradb/biblios/shadow:20G)
With the patch I don't see anything in the logs about shadow.  I do however see lines about merging.  I think it could just be a misunderstanding of the logs

Signed-off-by: wajasu <matted-34813@mypacks.net>
Signed-off-by: Elliott Davis <elliott@bywatersolutions.com>
Signed-off-by: Jared Camins-Esakov <jcamins@cpbibliography.com>

misc/migration_tools/rebuild_zebra.pl

@@ -93,6 +93,10 @@ if ($process_zebraqueue and $do_not_clear_zebraqueue) {
     die $msg;
 }
 
+if ($reset) {
+    $noshadow = 1;
+}
+
 if ($noshadow) {
     $noshadow = ' -n ';
 }
@@ -667,7 +671,7 @@ Parameters:
                             or -s.
 
     -r                      clear Zebra index before
-                            adding records to index
+                            adding records to index. Implies -w.
 
     -d                      Temporary directory for indexing.
                             If not specified, one is automatically