Fix allWarningsAsErrors mistake... Strange behaviour of Elvis operator in Groovy...

build.gradle

@@ -65,9 +65,8 @@ allprojects {
     tasks.withType(org.jetbrains.kotlin.gradle.tasks.KotlinCompile).all {
         // Warnings are potential errors, so stop ignoring them
         // You can override by passing `-PallWarningsAsErrors=false` in the command line
-        kotlinOptions.allWarningsAsErrors = project.properties['allWarningsAsErrors']?.toBoolean() ?: true
+        kotlinOptions.allWarningsAsErrors = project.getProperties().getOrDefault("allWarningsAsErrors", "true").toBoolean()
     }
-
 }
 
 task clean(type: Delete) {