[shotwell] Escape artist for extended properties

[Jens Georg <jensgeorg src gnome org>]

commit 76da910e50cc26cb5ab5cc95b8e9908f2fd9c646
Author: Jens Georg <mail jensge org>
Date:   Mon Mar 18 15:35:38 2019 +0100

    Escape artist for extended properties
    
    Fixes #112

 src/Properties.vala | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/src/Properties.vala b/src/Properties.vala
index 15b889af..1b4d0efe 100644
--- a/src/Properties.vala
+++ b/src/Properties.vala
@@ -645,7 +645,7 @@ private class ExtendedProperties : Properties {
             add_line(_("GPS longitude:"), (gps_long != -1 && gps_long_ref != "" &&
                 gps_long_ref != null) ? "%f °%s".printf(gps_long, gps_long_ref) : NO_VALUE, false, osm_link);
 
-            add_line(_("Artist:"), (artist != "" && artist != null) ? artist : NO_VALUE);
+            add_line(_("Artist:"), (artist != "" && artist != null) ? Markup.escape_text(artist) : NO_VALUE);
 
             add_line(_("Copyright:"), (copyright != "" && copyright != null) ? copyright : NO_VALUE);