Bug 1703229 - Fix some proton -moz-bool-pref usage that snook in yesterday. r=preferences-reviewers,Gijs

See bug 1698132 about why the media features are better (ltdr, they're
faster, easier to write, and don't need a restart to handle dynamic
changes).

Differential Revision: https://phabricator.services.mozilla.com/D110919

browser/components/aboutlogins/content/components/login-list.css

@@ -117,13 +117,13 @@ ol {
   border-top: 1px solid var(--in-content-border-color);
 }
 
-@supports not -moz-bool-pref("browser.proton.enabled") {
+@media not (-moz-proton) {
 .login-list-item:hover {
   background-color: var(--in-content-page-background);
 }
 } /*** END !proton ***/
 
-@supports -moz-bool-pref("browser.proton.enabled") {
+@media (-moz-proton) {
 .login-list-item:not(.selected):hover {
   background-color: var(--in-content-button-background-hover);
 }

browser/themes/shared/preferences/preferences.inc.css

@@ -572,7 +572,7 @@ checkbox {
   border-bottom: 1px solid var(--in-content-border-color);
 }
 
-@supports not -moz-bool-pref("browser.proton.enabled") {
+@media not (-moz-proton) {
 .dialogBox {
   border-radius: 3.5px;
 }