[mobile-broadband-provider-info] build: check for trailing whitespace

[Lubomir Rintel <lkundrak src gnome org>]

commit 37dc3f52e4a6e99abbc068c48ab76b91142012a5
Author: Lubomir Rintel <lkundrak v3 sk>
Date:   Thu Mar 17 09:18:52 2022 +0100

    build: check for trailing whitespace

 Makefile.am | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/Makefile.am b/Makefile.am
index a92c5be..3cdbcb8 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -18,5 +18,5 @@ apns-conf.xml: $(top_srcdir)/apns-conf.xsl $(top_srcdir)/$(SP_XML_DB)
 pkgdata_DATA = apns-conf.xml
 
 check-local:
-       grep '^[\t ]* <' serviceproviders.xml && exit 1 || :
+       grep $$'^[\t ]* <\|[ \t]$$' serviceproviders.xml && exit 1 || :
        xmllint --valid $(top_srcdir)/$(SP_XML_DB) 2>&1 >/dev/null