potential fix for build issues

publish.gradle

@@ -1,5 +1,4 @@
 apply plugin: 'maven-publish'
-apply plugin: 'signing'
 
 task javadocsJar(type: Jar) {
     classifier = 'javadoc'
@@ -20,22 +19,22 @@ publishing {
             }
 
             developers {
-                
+
                     developer {
                         id = "InsanusMokrassar"
                         name = "Ovsiannikov Aleksei"
                         email = "ovsyannikov.alexey95@gmail.com"
                     }
-                
+
             }
 
             licenses {
-                
+
                     license {
                         name = "MIT License"
                         url = "https://opensource.org/licenses/MIT"
                     }
-                
+
             }
         }
         repositories {
@@ -63,7 +62,11 @@ publishing {
     }
 }
 
-signing {
+if (System.getProperty("signatory.keyId") != null) {
-    useGpgCmd()
+    apply plugin: 'signing'
-    sign publishing.publications
+
+    signing {
+        useGpgCmd()
+        sign publishing.publications
+    }
 }