potential fix for build issues

publish.gradle

@@ -1,5 +1,4 @@
 apply plugin: 'maven-publish'
-apply plugin: 'signing'
 
 task javadocsJar(type: Jar) {
     classifier = 'javadoc'
@@ -63,7 +62,11 @@ publishing {
     }
 }
 
-signing {
+if (System.getProperty("signatory.keyId") != null) {
+    apply plugin: 'signing'
+
+    signing {
         useGpgCmd()
         sign publishing.publications
+    }
 }