[niepce] npc_engine: fix test build failure

[Hubert Figuière <hub src gnome org>]

commit aaa93c4961b77009502d793f427bdf78fdf04ed2
Author: Hubert Figuière <hub figuiere net>
Date:   Sat Feb 1 19:17:15 2020 -0500

    npc_engine: fix test build failure

 Cargo.lock                   | 1 +
 crates/npc-engine/Cargo.toml | 1 +
 crates/npc-engine/src/lib.rs | 1 +
 3 files changed, 3 insertions(+)
---
diff --git a/Cargo.lock b/Cargo.lock
index 00f69fc..af6b017 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -606,6 +606,7 @@ dependencies = [
  "cbindgen 0.8.4 (registry+https://github.com/rust-lang/crates.io-index)",
  "chrono 0.4.7 (registry+https://github.com/rust-lang/crates.io-index)",
  "exempi 2.5.0 (git+https://github.com/hfiguiere/exempi-rs.git?rev=53cfc05)",
+ "glib 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "libc 0.2.66 (registry+https://github.com/rust-lang/crates.io-index)",
  "npc-fwk 0.1.0",
  "pkg-config 0.3.14 (registry+https://github.com/rust-lang/crates.io-index)",
diff --git a/crates/npc-engine/Cargo.toml b/crates/npc-engine/Cargo.toml
index 5492f05..0b22aab 100644
--- a/crates/npc-engine/Cargo.toml
+++ b/crates/npc-engine/Cargo.toml
@@ -10,6 +10,7 @@ build = "build.rs"
 [dependencies]
 chrono = "0.4.0"
 exempi = { version = "2.5.0", git = "https://github.com/hfiguiere/exempi-rs.git";, rev="53cfc05" }
+glib = "*"
 libc = "0.2.39"
 rusqlite = { version = "0.14.0", features = ["functions"] }
 try_opt = "0.1.1"
diff --git a/crates/npc-engine/src/lib.rs b/crates/npc-engine/src/lib.rs
index 1f5f182..6602e78 100644
--- a/crates/npc-engine/src/lib.rs
+++ b/crates/npc-engine/src/lib.rs
@@ -17,6 +17,7 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+extern crate glib;
 #[macro_use]
 extern crate try_opt;