Actually add mysql driver

custom-dataflow-builds/dataflow-server-25x/README.adoc

@@ -11,10 +11,10 @@ should see executable jars to differ only with added mysql driver.
 $ ./test/build-and-compare
 
 Diff gradle build
-95a96
-> BOOT-INF/lib/mysql-connector-java-8.0.16.jar
+113a114
+> BOOT-INF/lib/mysql-connector-java-8.0.20.jar
 Diff maven build
-95a96
-> BOOT-INF/lib/mysql-connector-java-8.0.16.jar
+113a114
+> BOOT-INF/lib/mysql-connector-java-8.0.20.jar
 ```
 

custom-dataflow-builds/dataflow-server-25x/build.gradle

@@ -46,5 +46,6 @@ dependencyManagement {
 
 dependencies {
 	implementation 'org.springframework.cloud:spring-cloud-starter-dataflow-server'
+	runtime 'mysql:mysql-connector-java'
 	testImplementation 'org.springframework.boot:spring-boot-starter-test'
 }

custom-dataflow-builds/dataflow-server-25x/pom.xml

@@ -49,6 +49,10 @@
 			<artifactId>nimbus-jose-jwt</artifactId>
 			<version>${nimbus-jose-jwt.version}</version>
 		</dependency>
+		<dependency>
+			<groupId>mysql</groupId>
+			<artifactId>mysql-connector-java</artifactId>
+		</dependency>
 	</dependencies>
 
 	<dependencyManagement>