Bug 11694: [QA Followup] strip out time portion when setting suspension date for individual hold

This patch fixes an issue originally reported by bug 11702.

RM note: the patch is clear enough and doesn't break existing tests,
but on the other hand, I have been completely unable to reproduce
the original issue.

To test:

[1] Verify that prove -v t/db_dependent/Holds.t passes

Signed-off-by: Katrin Fischer <Katrin.Fischer.83@web.de>
Signed-off-by: Galen Charlton <gmc@esilibrary.com>

C4/Reserves.pm

@@ -1545,7 +1545,13 @@ be cleared when it is unsuspended.
 sub ToggleSuspend {
     my ( $reserve_id, $suspend_until ) = @_;
 
-    $suspend_until = output_pref({ dt => dt_from_string( $suspend_until ), dateformat => 'iso' }) if ( $suspend_until );
+    $suspend_until = output_pref(
+        {
+            dt         => dt_from_string($suspend_until),
+            dateformat => 'iso',
+            dateonly   => 1
+        }
+    ) if ($suspend_until);
 
     my $do_until = ( $suspend_until ) ? '?' : 'NULL';