pin deps to preserve MSRV

Author: RCasatta

Cargo.toml

@@ -19,11 +19,14 @@ which = "4.2.5"
 env_logger = "0.8"
 
 [build-dependencies]
-ureq = "1.0"  # allows to keep MSRV 1.41.1
 bitcoin_hashes = "0.10"
-flate2 = "1.0"
 tar = "0.4"
 
+# allows to keep MSRV 1.41.1
+ureq = "1.0"  
+filetime = "=0.2.15"
+flate2 = "=1.0.22"
+
 [features]
 "22_0" = []
 "0_21_1" = []