Bump tzf-rs, to fix empty result

Author: ringsaturn

Cargo.lock

@@ -1,7 +1,7 @@
 [package]
 edition = "2021"
 name = "tzfpy"
-version = "0.15.5"
+version = "0.15.6"
 
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
@@ -21,5 +21,5 @@ crate-type = ["cdylib"]
 lazy_static = "1.4.0"
 pyo3 = {version = "0.21.0", features = ["extension-module"]}
 
-# tzf-rs = { git =  "https://github.com/ringsaturn/tzf-rs", rev = "06a1bbf", default-features = false}
-tzf-rs = { version = "0.4.7", default-features = false }
+# tzf-rs = { git =  "https://github.com/ringsaturn/tzf-rs", rev = "31b1730", default-features = false}
+tzf-rs = { version = "0.4.8", default-features = false }