dos2unix: add build dependency on gettext (#17191)

var/spack/repos/builtin/packages/dos2unix/package.py

@@ -14,5 +14,7 @@ class Dos2unix(MakefilePackage):
 
     version('7.3.4', sha256='8ccda7bbc5a2f903dafd95900abb5bf5e77a769b572ef25150fde4056c5f30c5')
 
+    depends_on('gettext', type='build')
+
     def install(self, spec, prefix):
         make('prefix={0}'.format(prefix), 'install')