Move empty option to getExaminerNames

This was broken in PR aces#7462, so add it back to the same
place that it was removed from for more compatibility.

This also fixes the LINST instruments which weren't fixed
by adding it before the addSelect.

Author: driusan

php/libraries/NDB_BVL_Instrument.class.inc

@@ -911,7 +911,7 @@ abstract class NDB_BVL_Instrument extends NDB_Page
                 'Window Difference (+/- Days)'
             );
         }
-        $examiners = ['' => ''] + $this->_getExaminerNames();
+        $examiners = $this->_getExaminerNames();
         $this->addSelect('Examiner', 'Examiner', $examiners);
 
         $this->addRule(
@@ -1072,7 +1072,7 @@ abstract class NDB_BVL_Instrument extends NDB_Page
                 'examinerID'
             );
         }
-        $examiners = [];
+        $examiners = ['' => ''];
         if (is_array($results) && !empty($results)) {
             foreach ($results AS $eid => $row) {
                 $name = $row['full_name'];