Fix typos reported by codespell

contrib/debian/copyright

@@ -96,7 +96,7 @@ Comment: Site: https://bitcointalk.org/?topic=1756.0
 Files: src/qt/res/icons/proxy.png
        src/qt/res/src/proxy.svg
 Copyright: Cristian Mircea Messel
-Licese: public-domain
+License: public-domain
 
 
 License: Expat

contrib/gitian-build.py

@@ -170,7 +170,7 @@ def main():
 
     args.sign_prog = 'true' if args.detach_sign else 'gpg --detach-sign'
 
-    # Set enviroment variable USE_LXC or USE_DOCKER, let gitian-builder know that we use lxc or docker
+    # Set environment variable USE_LXC or USE_DOCKER, let gitian-builder know that we use lxc or docker
     if args.docker:
         os.environ['USE_DOCKER'] = '1'
     elif not args.kvm: