package/pngquant: replace utf-8 hyphen by ascii hyphen

Signed-off-by: Peter Seiderer <ps.report@gmx.net>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/pngquant/Config.in

@@ -3,7 +3,7 @@ config BR2_PACKAGE_PNGQUANT
 	select BR2_PACKAGE_LIBPNG
 	select BR2_PACKAGE_ZLIB
 	help
-	  Lossy PNG compressor — pngquant command and libimagequant
+	  Lossy PNG compressor - pngquant command and libimagequant
 	  library
 
 	  https://pngquant.org