SOVERSION bump to version 1.3.21
diff --git a/CMakeLists.txt b/CMakeLists.txt
index f42033f..4a192b0 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -48,7 +48,7 @@
 # with backward compatible change and micro version is connected with any internal change of the library.
 set(LIBNETCONF2_MAJOR_SOVERSION 1)
 set(LIBNETCONF2_MINOR_SOVERSION 3)
-set(LIBNETCONF2_MICRO_SOVERSION 20)
+set(LIBNETCONF2_MICRO_SOVERSION 21)
 set(LIBNETCONF2_SOVERSION_FULL ${LIBNETCONF2_MAJOR_SOVERSION}.${LIBNETCONF2_MINOR_SOVERSION}.${LIBNETCONF2_MICRO_SOVERSION})
 set(LIBNETCONF2_SOVERSION ${LIBNETCONF2_MAJOR_SOVERSION})