Fix create-both-builds macro

macros/create_both_builds.asc

@@ -4,7 +4,7 @@
 // to see how this macro is used for writing Getting Started guides.
 //
 === Create a Gradle build file
-Below is the https://github.com/spring-guides/${project_id}/blob/master/initial/build.gradle[initial Gradle build file]. But you can also use Maven. The pom.xml file is included https://github.com/spring-guides/${project_id}/blob/master/initial/pom.xml[right here]. If you are using link:/guides/gs/sts[Spring Tool Suite (STS)], you can import the guide directly.
+Below is the https://github.com/spring-guides/{project_id}/blob/master/initial/build.gradle[initial Gradle build file]. But you can also use Maven. The pom.xml file is included https://github.com/spring-guides/{project_id}/blob/master/initial/pom.xml[right here]. If you are using link:/guides/gs/sts[Spring Tool Suite (STS)], you can import the guide directly.
 
 // AsciiDoc source formatting doesn't support groovy, so using java instead
 [source,java]