tde_create_translated_desktop: Fix CMP0054 warning in case of special

desktop file name that could be the same as the keyword.

Signed-off-by: Slávek Banko <slavek.banko@axis.cz>
(cherry picked from commit 9f86304bdd)

modules/TDEMacros.cmake

@@ -1898,7 +1898,7 @@ macro( tde_create_translated_desktop )
     file( MAKE_DIRECTORY "${_binary_basedir}" )
 
     # process source file as a configuration file if necessary
-    if( "${_src}" MATCHES "\\.cmake$" )
+    if( "+${_src}" MATCHES "\\.cmake$" )
       configure_file( ${_src} ${_basename} @ONLY )
       set( _src "${CMAKE_CURRENT_BINARY_DIR}/${_basename}" )
       string( REGEX REPLACE "\\.cmake$" "" _basename "${_basename}" )