Remove [target.'cfg(debug_assertions)'.dependencies] in contrib Cargo…

….toml.

This is not supported and is the same as putting the contents in
[dependencies] anyway. It became a warning in rust-lang/cargo#7660.

Backport of 4151cd4.

contrib/lib/Cargo.toml

@@ -51,6 +51,7 @@ rmp-serde = { version = "^0.13", optional = true }
 handlebars = { version = "1.0", optional = true }
 glob = { version = "0.3", optional = true }
 tera = { version = "0.11", optional = true }
+notify = { version = "4.0.6" }
 
 # UUID dependencies.
 uuid = { version = "0.7", optional = true }
@@ -76,8 +77,5 @@ r2d2-memcache = { version = "0.3", optional = true }
 # SpaceHelmet dependencies
 time = { version = "0.1.40", optional = true }
 
-[target.'cfg(debug_assertions)'.dependencies]
-notify = { version = "^4.0.6" }
-
 [package.metadata.docs.rs]
 all-features = true