configure.ac: move some gettext checks to conditional block

configure.ac

@@ -16,14 +16,7 @@ AC_CONFIG_MACRO_DIR([m4])
 
 AC_CHECK_HEADERS([dbox/fp.h dbox/lcd-ks0713.h])
 
-AC_PATH_PROG(MSGFMT,[msgfmt])
-AC_PATH_PROG(MSGINIT,[msginit])
-AC_PATH_PROG(MSGMERGE,[msgmerge])
-AC_PATH_PROG(MSGUNIQ,[msguniq])
-AC_PATH_PROG(XGETTEXT,[xgettext])
-if test -z "$MSGFMT" -o -z "$MSGINIT" -o -z "$MSGMERGE" -o -z "$MSGUNIQ" -o -z "$XGETTEXT"; then
-	AC_MSG_ERROR([Could not find required gettext tools])
-fi
+AC_PATH_PROG(MSGFMT, msgfmt, AC_MSG_ERROR(Could not find msgfmt))
 
 AM_PATH_PYTHON
 AX_PYTHON_DEVEL
@@ -88,6 +81,15 @@ fi
 AC_ARG_WITH(po,
 	AS_HELP_STRING([--with-po],[enable updating of po files]),
 	[with_po="$withval"],[with_po="no"])
+if test "$with_po" = "yes"; then
+	AC_PATH_PROG(MSGINIT, msginit)
+	AC_PATH_PROG(MSGMERGE, msgmerge)
+	AC_PATH_PROG(MSGUNIQ, msguniq)
+	AC_PATH_PROG(XGETTEXT, xgettext)
+	if test -z "$MSGINIT" -o -z "$MSGMERGE" -o -z "$MSGUNIQ" -o -z "$XGETTEXT"; then
+		AC_MSG_ERROR([Could not find required gettext tools])
+	fi
+fi
 AM_CONDITIONAL(UPDATE_PO, test "$with_po" = "yes")
 
 CPPFLAGS="$CPPFLAGS $PYTHON_CPPFLAGS"