Fix GitHub Action yaml for Gradle build

git-svn-id: https://svn.apache.org/repos/asf/poi/trunk@1886449 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/.github/workflows/test-gradle.yml b/.github/workflows/test-gradle.yml
index 56931c2..9822eef 100644
--- a/.github/workflows/test-gradle.yml
+++ b/.github/workflows/test-gradle.yml
@@ -32,7 +32,7 @@
         restore-keys: |
           ${{ runner.os }}-gradle-
 
-    - name:Verify Gradle wrapper
+    - name: Verify Gradle wrapper
       uses: gradle/wrapper-validation-action@v1
 
     - name: Grant execute permission for gradlew