[build][version] more accurate version string for local builds (drops -1 in build number)

shared/buildSrc/src/main/kotlin/org/jetbrains/kotlin/VersionGenerator.kt

@@ -52,10 +52,12 @@ open class VersionGenerator: DefaultTask() {
                      |       }
                      |       append('-')
                      |       append(meta.metaString)
+                     |       if (build != -1) {
                      |         append('-')
                      |         append(build)
                      |       }
                      |     }
+                     |  }
                      |  override fun toString() = versionString
                      |}
             """.trimMargin()