Support case of non-existent Version.properties file.

build.gradle

@@ -119,10 +119,14 @@ task updateVersion {
 
     doLast {
         def oldProps = new Properties()
-        file(versionFile).withInputStream { stream -> oldProps.load(stream) }
-        def oldFullVersion = oldProps['version']
+        String oldFullVersion, fullVersion
 
-        String fullVersion
+        try {
+            file(versionFile).withInputStream { stream -> oldProps.load(stream) }
+            oldFullVersion = oldProps['version']
+        } catch (ignored) {
+            oldFullVersion = "???"
+        }
         try {
             def proc = 'git describe'.execute(null, rootDir)
             if  (proc.waitFor() == 0) {