Adjust uploadArchives task

de.ugoe.cs.rwm.mocci.connector.dummy/build.gradle

@@ -44,7 +44,10 @@ uploadArchives {
              repository(url: "https://nexus.informatik.uni-goettingen.de/content/repositories/rwm/") {
              authentication(userName: System.getenv('NEXUSUSER'), password: System.getenv('NEXUSPASSWORD'))
             }
-            pom.version = System.getenv('VERSION')
+                        if (System.getenv('VERSION') != null) {
+                  pom.version = System.getenv('VERSION')
+                  println "Version is set to: " + System.getenv('VERSION')
+             }
              pom.artifactId = "connector"
              pom.groupId = "de.ugoe.cs.rwm.mocci"
        }

de.ugoe.cs.rwm.mocci.connector/build.gradle

@@ -39,7 +39,10 @@ uploadArchives {
              repository(url: "https://nexus.informatik.uni-goettingen.de/content/repositories/rwm/") {
              authentication(userName: System.getenv('NEXUSUSER'), password: System.getenv('NEXUSPASSWORD'))
             }
-            pom.version = System.getenv('VERSION')
+                        if (System.getenv('VERSION') != null) {
+                  pom.version = System.getenv('VERSION')
+                  println "Version is set to: " + System.getenv('VERSION')
+             }
              pom.artifactId = "connector"
              pom.groupId = "de.ugoe.cs.rwm.mocci"
        }

de.ugoe.cs.rwm.mocci.model.edit/build.gradle

@@ -43,7 +43,10 @@ uploadArchives {
              repository(url: "https://nexus.informatik.uni-goettingen.de/content/repositories/rwm/") {
              authentication(userName: System.getenv('NEXUSUSER'), password: System.getenv('NEXUSPASSWORD'))
             }
-            pom.version = System.getenv('VERSION')
+                        if (System.getenv('VERSION') != null) {
+                  pom.version = System.getenv('VERSION')
+                  println "Version is set to: " + System.getenv('VERSION')
+             }
              pom.artifactId = "edit"
              pom.groupId = "de.ugoe.cs.rwm.mocci.model"
        }

de.ugoe.cs.rwm.mocci.model/build.gradle

@@ -73,7 +73,10 @@ uploadArchives {
              repository(url: "https://nexus.informatik.uni-goettingen.de/content/repositories/rwm/") {
              authentication(userName: System.getenv('NEXUSUSER'), password: System.getenv('NEXUSPASSWORD'))
             }
-            pom.version = System.getenv('VERSION')
+                       if (System.getenv('VERSION') != null) {
+                  pom.version = System.getenv('VERSION')
+                  println "Version is set to: " + System.getenv('VERSION')
+             }
              pom.artifactId = "model"
              pom.groupId = "de.ugoe.cs.rwm.mocci"
        }