Null check for player textures in GameProfile

Fixes an issue with the ZNPCs plugin.

core/src/main/java/org/geysermc/geyser/skin/SkinManager.java

@@ -240,7 +240,12 @@ public class SkinManager {
                     // Likely offline mode
                     return loadBedrockOrOfflineSkin(profile);
                 }
-                return loadFromJson(skinProperty.getValue());
+                GameProfileData data = loadFromJson(skinProperty.getValue());
+                if (data != null) {
+                    return data;
+                } else {
+                    return loadBedrockOrOfflineSkin(profile);
+                }
             } catch (IOException exception) {
                 GeyserImpl.getInstance().getLogger().debug("Something went wrong while processing skin for " + profile.getName());
                 if (GeyserImpl.getInstance().getConfig().isDebugMode()) {
@@ -254,6 +259,7 @@ public class SkinManager {
             JsonNode skinObject = GeyserImpl.JSON_MAPPER.readTree(new String(Base64.getDecoder().decode(encodedJson), StandardCharsets.UTF_8));
             JsonNode textures = skinObject.get("textures");
 
+            if (textures != null) {
                 JsonNode skinTexture = textures.get("SKIN");
                 String skinUrl = skinTexture.get("url").asText().replace("http://", "https://");
 
@@ -267,6 +273,8 @@ public class SkinManager {
 
                 return new GameProfileData(skinUrl, capeUrl, isAlex);
             }
+            return null;
+        }
 
         /**
          * @return default skin with default cape when texture data is invalid, or the Bedrock player's skin if this