Update package.json

Author: 奇淼（piexlmax

web/package.json

@@ -14,7 +14,7 @@
         "axios": "^0.19.2",
         "core-js": "^3.6.5",
         "echarts": "4.9.0",
-        "element-plus": "1.3.0-beta.8",
+        "element-plus": "1.2.0-beta.6",
         "highlight.js": "^10.6.0",
         "marked": "^2.0.0",
         "mitt": "^3.0.0",