increment librtlsdr version from 0.8 to 2.1

* to keep it compatible with
 https://github.com/steve-m/librtlsdr/tree/v2.0.1 and
 https://github.com/osmocom/rtl-sdr/tree/v2.0.1
* see issue #134

Signed-off-by: hayati ayguen <h_ayguen@web.de>

CMakeLists.txt

@@ -48,8 +48,8 @@ OPTION(PROVIDE_UDP_SERVER "Provide UDP server for tests" OFF)
 OPTION(WITH_RPC "RPC for non-Windows" OFF)
 
 # Set the version information here
-set(VERSION_INFO_MAJOR_VERSION 0) # increment major on api compatibility changes
-set(VERSION_INFO_MINOR_VERSION 8) # increment minor on feature-level changes
+set(VERSION_INFO_MAJOR_VERSION 2) # increment major on api compatibility changes
+set(VERSION_INFO_MINOR_VERSION 1) # increment minor on feature-level changes
 set(VERSION_INFO_PATCH_VERSION git) # increment patch for bug fixes and docs
 include(Version) # setup version info