Fix JdbcMessageStoreTests to use H2, not Derby

Looks like Derby is much slower than H2, plus it doesn't look so stable
having so much sporadic failures.

Looks like moving to H2 here saves for us `500 ms` test working time

**Cherry-pick to 5.0.x**

spring-integration-jdbc/src/test/java/org/springframework/integration/jdbc/store/JdbcMessageStoreTests-context.xml

@@ -2,21 +2,12 @@
 <beans xmlns="http://www.springframework.org/schema/beans"
 	   xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 	   xmlns:jdbc="http://www.springframework.org/schema/jdbc"
-	   xmlns:context="http://www.springframework.org/schema/context"
 	   xsi:schemaLocation="http://www.springframework.org/schema/jdbc http://www.springframework.org/schema/jdbc/spring-jdbc.xsd
-			http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
-			http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd">
+			http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">
 
-	<jdbc:embedded-database id="dataSource" type="DERBY"/>
-
-	<jdbc:initialize-database data-source="dataSource">
-		<jdbc:script location="${int.schema.script}"/>
-	</jdbc:initialize-database>
-
-	<context:property-placeholder location="int-${ENVIRONMENT:derby}.properties"
-								  system-properties-mode="OVERRIDE"
-								  ignore-unresolvable="true"
-								  order="1"/>
+	<jdbc:embedded-database id="dataSource" type="H2">
+		<jdbc:script location="org/springframework/integration/jdbc/schema-h2.sql" />
+	</jdbc:embedded-database>
 
 	<bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
 		<property name="dataSource" ref="dataSource"/>