[librsvg-oci-images] Install rustfmt in openSUSE

[Federico Mena Quintero <federico src gnome org>]

commit ac0076f3c98eacc6f7838c994be23add4ee63124
Author: Federico Mena Quintero <federico gnome org>
Date:   Thu Feb 6 16:55:31 2020 -0600

    Install rustfmt in openSUSE
    
    We need this for the "cargo fmt" step in librsvg's CI.

 opensuse/prepare.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/opensuse/prepare.sh b/opensuse/prepare.sh
index ebaf9b8..d543ca5 100644
--- a/opensuse/prepare.sh
+++ b/opensuse/prepare.sh
@@ -1,7 +1,7 @@
 #!/bin/sh
 
 zypper update -y
-zypper install -y gcc rust cargo make vala \
+zypper install -y gcc rust cargo rustfmt make vala \
     automake autoconf libtool gettext itstool git \
     gtk-doc gobject-introspection-devel gtk3-devel \
     libxml2-devel libcroco-devel cairo-devel \