tde_create_translated_desktop: Fix processing when using configure_file.

Although the processing with configure_file was done properly,
the original source file was used instead of the processed one
to merge the translations.

Signed-off-by: Slávek Banko <slavek.banko@axis.cz>
(cherry picked from commit 3bbc0e4d62)

modules/TDEMacros.cmake

@@ -1900,7 +1900,7 @@ macro( tde_create_translated_desktop )
     # process source file as a configuration file if necessary
     if( "${_src}" MATCHES "\\.cmake$" )
       configure_file( ${_src} ${_basename} @ONLY )
-      set( ${_src} "${CMAKE_CURRENT_BINARY_DIR}/${_basename}" )
+      set( _src "${CMAKE_CURRENT_BINARY_DIR}/${_basename}" )
       string( REGEX REPLACE "\\.cmake$" "" _basename "${_basename}" )
     endif()