Edit note form should use consistent background color

When editing an issue, the background color for the text area should be
consistent with the class of private vs. public notes.

Issue #21697

bugnote_edit_page.php

@@ -109,6 +109,8 @@
 layout_page_header( bug_format_summary( $t_bug_id, SUMMARY_CAPTION ) );
 
 layout_page_begin();
+
+$t_bugnote_class = bugnote_get_field( $f_bugnote_id, 'view_state' ) == VS_PUBLIC ? '' : 'bugnote-private';
 ?>
 <div class="col-md-12 col-xs-12">
 
@@ -128,7 +130,8 @@
 <table class="table table-bordered table-condensed table-striped">
 <tr>
 	<td class="center" colspan="2">
-		<textarea class="form-control" cols="80" rows="10" name="bugnote_text"><?php echo $t_bugnote_text ?></textarea>
+		<textarea class="form-control <?php echo $t_bugnote_class; ?>" cols="80" rows="10" name="bugnote_text"
+		><?php echo $t_bugnote_text ?></textarea>
 	</td>
 </tr>
 <?php if( config_get( 'time_tracking_enabled' ) ) { ?>