fixed url for background image in combined_styles.css

flask_app/app/templates/combined_styles.css

@@ -109,7 +109,7 @@ margin: 0 auto
 .logo-area {
 width: 180px;
 height: 60px;
-background-image: url(""{{ url_for("static", filename=static_prefix+"css/alteram/alteram1_1_600x197.png") }}");
+background-image: url("{{ url_for("static", filename=static_prefix+"css/alteram/alteram1_1_600x197.png") }}");
 background-size: contain;
 background-repeat: no-repeat;
 background-position: left center;