Remove Java version override

Author: sdeleuze

README.adoc

@@ -43,7 +43,6 @@ response, as the following listing shows:
 
 == What You Need
 
-:java_version: 1.8
 include::https://raw.githubusercontent.com/spring-guides/getting-started-macros/main/prereq_editor_jdk_buildtools.adoc[]
 
 include::https://raw.githubusercontent.com/spring-guides/getting-started-macros/main/how_to_complete_this_guide.adoc[]