[gthumb] Fixed git url in README

[Paolo Bacchilega <paobac src gnome org>]

commit ec9c9d814ad93ba71aa26697db0ab1a8ec464771
Author: Paolo Bacchilega <paobac src gnome org>
Date:   Sat Apr 20 18:59:41 2019 +0200

    Fixed git url in README
    
    Fixes https://gitlab.gnome.org/GNOME/gthumb/issues/40

 README | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/README b/README
index 7757600a..dd6f6dbe 100644
--- a/README
+++ b/README
@@ -122,7 +122,7 @@ Download
   * You can download and compile the latest development version using the
     following commands:
 
-        git clone git://git.gnome.org/gthumb
+        git clone https://gitlab.gnome.org/GNOME/gthumb.git
         cd gthumb
         meson build
         ninja -C build