obexd: Fix missing URL vCard's field with OTHER subtype

Previously URL vCard's field (imported with default OTHER subtype) was
missing after pulling entire phonebook or single vCard (for phonebook
and each call history as well).
This patch fixes that issue by adjusting queries to URL field.
diff --git a/obexd/plugins/phonebook-tracker.c b/obexd/plugins/phonebook-tracker.c
index e4f2383..a8b97c2 100644
--- a/obexd/plugins/phonebook-tracker.c
+++ b/obexd/plugins/phonebook-tracker.c
@@ -115,7 +115,7 @@
 "nco:birthDate(?_contact) "						\
 "nco:nickname(?_contact) "						\
 "(SELECT GROUP_CONCAT(fn:concat( "					\
-	"?url_val, \"\31\", rdfs:label(?_role) "			\
+	"?url_val, \"\31\", tracker:coalesce(rdfs:label(?_role), \"\") "\
 	"), \"\30\") "							\
 	"WHERE {"							\
 		"?_role nco:url ?url_val . "				\
@@ -224,13 +224,11 @@
 	"}) "								\
 	"nco:birthDate(?_contact) "					\
 	"nco:nickname(?_contact) "					\
-"(SELECT GROUP_CONCAT(fn:concat( "					\
-	"?url_value, \"\31\", ?aff_type "				\
-	"), \"\30\") "							\
+"(SELECT GROUP_CONCAT(fn:concat(?url_value, \"\31\", "			\
+	"tracker:coalesce(rdfs:label(?c_role), \"\")), \"\30\") "	\
 	"WHERE {"							\
 		"?_contact nco:hasAffiliation ?c_role . "		\
 		"?c_role nco:url ?url_value . "				\
-		"?c_role rdfs:label ?aff_type . "			\
 "})"									\
 	"nie:url(nco:photo(?_contact)) "				\
 	"nco:role(?_role) "						\
@@ -320,7 +318,7 @@
 "nco:birthDate(<%s>) "							\
 "nco:nickname(<%s>) "							\
 "(SELECT GROUP_CONCAT(fn:concat( "					\
-	"?url_val, \"\31\", rdfs:label(?_role) "			\
+	"?url_val, \"\31\", tracker:coalesce(rdfs:label(?_role), \"\") "\
 	"), \"\30\") "							\
 	"WHERE {"							\
 		"?_role nco:url ?url_val . "				\