fix: fix 助手回答为空的情况。

answer 变量只有写没有读，既然 component.text 能存，就直接写到这好了，不再加变量了。

Author: iptton

src/main/kotlin/cc/unitmesh/devti/gui/chat/MessageView.kt

@@ -23,7 +23,6 @@ class MessageView(private val message: String, val role: ChatRole, private val d
     JBPanel<MessageView>() {
     private val myNameLabel: Component
     private val component: DisplayComponent = DisplayComponent(message)
-    private var answer: String? = null
     private var centerPanel: JPanel = JPanel(VerticalLayout(JBUI.scale(8)))
 
     init {
@@ -106,7 +105,7 @@ class MessageView(private val message: String, val role: ChatRole, private val d
     }
 
     fun updateSourceContent(source: String?) {
-        answer = source
+        component.text = source
     }
 
     fun scrollToBottom() {
@@ -238,4 +237,4 @@ class MessageView(private val message: String, val role: ChatRole, private val d
         }
 
     }
-}
+}