Change Gtk Version number in sample description (#3741)
Change Gtk Version number in sample description (#3741)

The sample project is using Gtk3 and not Gtk2
JetBrains/kotlin-native,JetBrains/kotlin-native,wiltonlazary/kotlin-native,JetBrains/kotlin-native,JetBrains/kotlin-native,wiltonlazary/kotlin-native,JetBrains/kotlin-native,wiltonlazary/kotlin-native,wiltonlazary/kotlin-native,JetBrains/kotlin-native,JetBrains/kotlin-native,JetBrains/kotlin-native,JetBrains/kotlin-native,wiltonlazary/kotlin-native