runtime-modules: Cargo.toml tweak

runtime-modules/versioned-store-permissions/Cargo.toml

@@ -5,7 +5,7 @@ authors = ['Joystream contributors']
 edition = '2018'
 
 [dependencies]
-serde = { version = "1.0.101", features = ["derive"] }
+serde = { version = "1.0.101", optional = true, features = ["derive"] }
 codec = { package = 'parity-scale-codec', version = '1.3.1', default-features = false, features = ['derive'] }
 sp-std = { package = 'sp-std', default-features = false, git = 'https://github.com/paritytech/substrate.git', rev = '00768a1f21a579c478fe5d4f51e1fa71f7db9fd4'}
 frame-support = { package = 'frame-support', default-features = false, git = 'https://github.com/paritytech/substrate.git', rev = '00768a1f21a579c478fe5d4f51e1fa71f7db9fd4'}
@@ -23,6 +23,7 @@ common = { package = 'pallet-common', default-features = false, path = '../commo
 [features]
 default = ['std']
 std = [
+	'serde',
 	'codec/std',
 	'sp-std/std',
 	'frame-support/std',