refactor build.gradle to improve version handling and email

configuration

Author: tonivade

build.gradle

@@ -9,8 +9,6 @@ plugins {
 
 group = 'com.github.tonivade'
 
-ext.isReleaseVersion = !version.endsWith("SNAPSHOT")
-
 java {
   toolchain {
     languageVersion = JavaLanguageVersion.of(11)
@@ -118,23 +116,24 @@ publishing {
           developer {
             id = 'tonivade'
             name = 'Antonio Muñoz'
-            email = 'antoniogmc@gmail.com'
+            email = 'me@tonivade.es'
           }
         }
       }
     }
   }
 }
 
-signing {
-  def signingKey = project.findProperty("signingKey")
-  def signingPassword = project.findProperty("signingPassword")
-  useInMemoryPgpKeys(signingKey, signingPassword)
-  sign publishing.publications.mavenJava
-}
+def isReleaseVersion = !version.endsWith("SNAPSHOT")
 
-tasks.withType(Sign) {
-  onlyIf { isReleaseVersion }
+signing {
+  def signingKey = providers.gradleProperty("signingKey")
+  def signingPassword = providers.gradleProperty("signingPassword")
+  useInMemoryPgpKeys(signingKey.orNull, signingPassword.orNull)
+  
+  if (isReleaseVersion) {
+    sign publishing.publications.mavenJava
+  }
 }
 
 nexusPublishing {