DRILL-8207: Fix typo in JDBC config (#2530)

diff --git a/contrib/storage-jdbc/src/main/java/org/apache/drill/exec/store/jdbc/JdbcStorageConfig.java b/contrib/storage-jdbc/src/main/java/org/apache/drill/exec/store/jdbc/JdbcStorageConfig.java
index b8d915c..55753a2 100644
--- a/contrib/storage-jdbc/src/main/java/org/apache/drill/exec/store/jdbc/JdbcStorageConfig.java
+++ b/contrib/storage-jdbc/src/main/java/org/apache/drill/exec/store/jdbc/JdbcStorageConfig.java
@@ -91,7 +91,7 @@
     this.writerBatchSize = that.writerBatchSize;
   }
 
-  @JsonProperty("userName")
+  @JsonProperty("username")
   public String getUsername() {
     if (!directCredentials) {
       return null;