Merge pull request #2753 from baomidou/dependabot/gradle/springVersion-5.2.8.RELEASE

Bump springVersion from 5.2.7.RELEASE to 5.2.8.RELEASE

build.gradle

@@ -23,7 +23,7 @@ ext {
         mybatisVersion = '3.5.5',
         mybatisSpringVersion = '2.0.5',
         mybatisSpringBootStarterVersion = '2.1.3',
-        springVersion = '5.2.7.RELEASE',
+        springVersion = '5.2.8.RELEASE',
         springBootVersion = '2.3.1.RELEASE',
         jsqlparserVersion = '3.2',
         junitVersion = '5.6.2',