fix meson.build for latest version

meson.build

@@ -45,7 +45,7 @@ project(
         'cpp_std=gnu++17',
         'b_asneeded=false', # required on some platforms
     ],
-    version : '2.2pre1', # should agree with binary_c_version.h
+    version : '2.2.0', # should agree with binary_c_version.h
 )
 
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