remove sgsgb-related stuff

public/static/config.json

@@ -25,7 +25,7 @@
   "sidebarRight": false,
   "subjectLineBehavior": "email",
   "theme": null,
-  "style": "BreezyDX",
-  "palette": "sigsegv2",
+  "style": null,
+  "palette": null,
   "webPushNotifications": false
 }

public/static/palettes/index.json

@@ -1,6 +1,4 @@
 {
-  "sigsegv": [ "シグセグＶ", "#100f32", "#221548", "#e6fcff", "#fe9df8", "#fd3f3f", "#cafeb8", "#9fd3fe", "#ffe96b" ],
-  "sigsegv2": [ "SigSeg部", "#003238", "#00616c", "#e8f9fb", "#81ffff", "#ff7b66", "#4ae619", "#00ddff", "#ccef53" ],
   "pleroma-dark": [ "Pleroma Dark", "#121a24", "#182230", "#b9b9ba", "#d8a070", "#d31014", "#0fa00f", "#0095ff", "#ffa500" ],
   "pleroma-light": [ "Pleroma Light", "#f2f4f6", "#dbe0e8", "#304055", "#f86f0f", "#d31014", "#0fa00f", "#0095ff", "#ffa500" ],
   "classic-dark": {