Bump version to 1.2.1

The v1.2.0 release is borked. It has wrong project version in
CMakeLists.txt, 1.1.0 instead of 1.2.0.
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 0228c32..2097dbc 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,6 +1,6 @@
 cmake_minimum_required(VERSION 3.5)
 
-project(PlasmaWaylandProtocols VERSION 1.2.0)
+project(PlasmaWaylandProtocols VERSION 1.2.1)
 
 include(FeatureSummary)
 include(CMakePackageConfigHelpers)