Revert "Start building against Dependency Management Plugin 1.0.5 snapshots"

Uses snapshots of the Dependency Management Plugin causes problems as
they are only published to our plugins-snapshot repository which may
not be configured in someone's build.

See gh-12406

spring-boot-parent/pom.xml

@@ -81,7 +81,7 @@
 			<dependency>
 				<groupId>io.spring.gradle</groupId>
 				<artifactId>dependency-management-plugin</artifactId>
-				<version>1.0.5.BUILD-SNAPSHOT</version>
+				<version>1.0.4.RELEASE</version>
 			</dependency>
 			<dependency>
 				<groupId>jline</groupId>