!100 fix-key-reference-mismatch

Merge pull request !100 from Xiaoxi121/fix-key-reference-mismatch

im-server/src/main/java/com/bx/imserver/constant/ChannelAttrKey.java

@@ -16,6 +16,6 @@ public final class ChannelAttrKey {
     /**
      * 心跳次数
      */
-    public static final String HEARTBEAT_TIMES = "HEARTBEAt_TIMES";
+    public static final String HEARTBEAT_TIMES = "HEARTBEAT_TIMES";
 
 }