Remove old grey palette from dark theme

customize.dist/src/less2/include/colortheme-dark.less

@@ -31,16 +31,6 @@
 @cryptpad_color_brand_fader: fade(@cryptpad_color_brand, 50%);
 @cryptpad_color_brand_fadest: fade(@cryptpad_color_brand, 25%);
 
-@cryptpad_color_hint_grey: #777;
-@cryptpad_color_dark_grey: #999999;
-@cryptpad_color_neutral_grey: #aaaaaa;
-@cryptpad_color_neutral2_grey: #cccccc;
-@cryptpad_color_help_grey: #dddddd;
-@cryptpad_color_grey: #e0e0e0;
-@cryptpad_color_toolbar_grey: #EEEEEE;
-@cryptpad_color_light_grey: #f1f1f1;
-@cryptpad_color_lighter_grey: #f9f9f9;
-
 @cryptpad_color_white: #FFF;
 @cryptpad_color_grey_50: #FAFAFA;
 @cryptpad_color_grey_100: #F5F5F5;

customize.dist/src/less2/include/sidebar-layout.less

@@ -110,7 +110,7 @@
                 input {
                     flex: 1;
                     //border-radius: 0.25em 0 0 0.25em;
-                    border: 1px solid @cryptpad_color_neutral_grey;
+                    border: 1px solid @cryptpad_color_grey_500;
                     border-right: 0px;
                 }
                 button {