修改core-fss，修复配置项限制

Signed-off-by: luoshi <luoshi@qmth.com.cn>

core-fss/src/main/java/com/qmth/boot/core/fss/config/FileStoreProperty.java

@@ -10,6 +10,7 @@ public class FileStoreProperty {
     @NotNull
     private String config;
 
+    @NotNull
     private String server;
 
     public String getConfig() {