Move border-radius from #main to .window elements to fix radius once and for all

https://github.com/thelounge/lounge/pull/537 only fixed it on chat windows,
but for some browser-specific display bug/reason not on settings, login, ...

client/css/style.css

@@ -587,11 +587,8 @@ button {
 }
 
 #main {
-	background: #fff;
-	border-radius: 2px;
 	bottom: 4px;
 	left: 220px;
-	overflow: hidden; /* Without this, border-radius has no effect */
 	position: absolute;
 	right: 5px;
 	top: 4px;
@@ -651,6 +648,7 @@ button {
 
 #windows .window {
 	background: #fff;
+	border-radius: 2px;
 	bottom: 0;
 	display: none;
 	left: 0;

client/themes/crypto.css

@@ -38,6 +38,9 @@ a:hover,
 	right: 0;
 	bottom: 0;
 	top: 0;
+}
+
+#windows .window {
 	border-radius: 0;
 }
 

client/themes/morning.css

@@ -70,12 +70,16 @@ body {
 	left: 0;
 	bottom: 0;
 	width: 220px;
+	border-radius: 0;
 }
 
 #main {
 	top: 0;
 	bottom: 0;
 	right: 0;
+}
+
+#windows .window {
 	border-radius: 0;
 }
 

client/themes/zenburn.css

@@ -97,12 +97,16 @@ body {
 	left: 0;
 	bottom: 0;
 	width: 220px;
+	border-radius: 0;
 }
 
 #main {
 	top: 0;
 	bottom: 0;
 	right: 0;
+}
+
+#windows .window {
 	border-radius: 0;
 }