TranslateDesktop: Use -a switch in grep commands

As of grep v2.23 some translation files are considered as binary (maybe because of some locale settings)
and then the created .desktop file is malformed. So we force the grep to handle all provided input
files as text.

closes lxqt/lxqt#957

cmake/modules/LXQtTranslateDesktop.cmake

@@ -71,13 +71,13 @@ function(lxqt_translate_desktop _RESULT)
         if (_translations)
             list(SORT _translations)
             add_custom_command(OUTPUT ${_outFile}
-                COMMAND grep -v "'#TRANSLATIONS_DIR='" ${_inFile} > ${_outFile}
-                COMMAND grep -h ${_pattern} ${_translations} >> ${_outFile}
+                COMMAND grep -v -a "'#TRANSLATIONS_DIR='" ${_inFile} > ${_outFile}
+                COMMAND grep -h -a ${_pattern} ${_translations} >> ${_outFile}
                 COMMENT "Generating ${_fileName}${_fileExt}"
             )
         else()
             add_custom_command(OUTPUT ${_outFile}
-                COMMAND grep -v "'#TRANSLATIONS_DIR='" ${_inFile} > ${_outFile}
+                COMMAND grep -v -a "'#TRANSLATIONS_DIR='" ${_inFile} > ${_outFile}
                 COMMENT "Generating ${_fileName}${_fileExt}"
             )
         endif()