[librsvg] state::get_font_family() should return an Option<String>

[Federico Mena Quintero <federico src gnome org>]

commit cda0462a3b2103938a4de15b7ef4634d37341edb
Author: Federico Mena Quintero <federico gnome org>
Date:   Fri Dec 15 09:10:25 2017 -0600

    state::get_font_family() should return an Option<String>

 rust/src/state.rs | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)
---
diff --git a/rust/src/state.rs b/rust/src/state.rs
index cd4dcba..5e60eb3 100644
--- a/rust/src/state.rs
+++ b/rust/src/state.rs
@@ -43,11 +43,10 @@ pub fn get_text_gravity(state: *const RsvgState) -> pango::Gravity {
     unsafe { from_glib(rsvg_state_get_text_gravity(state)) }
 }
 
-pub fn get_font_family(state: *const RsvgState) -> String {
+pub fn get_font_family(state: *const RsvgState) -> Option<String> {
     unsafe { from_glib_none(rsvg_state_get_font_family(state)) }
 }
 
-
 pub fn get_font_style(state: *const RsvgState) -> pango::Style {
     unsafe { from_glib(rsvg_state_get_font_style(state)) }
 }