Use dependencies we already have in the ports tree.

Index: setup.py
--- setup.py.orig
+++ setup.py
@@ -17,11 +17,11 @@ deps = [
 ]
 
 # for encrypted streams
-if environ.get("STREAMLINK_USE_PYCRYPTO"):
-    deps.append("pycrypto")
-else:
+if environ.get("STREAMLINK_USE_PYCRYPTODOME"):
     # this version of pycryptodome is known to work and has a Windows wheel for py2.7, py3.3-3.6
     deps.append("pycryptodome>=3.4.3,<4")
+else:
+    deps.append("pycryptodome")
 
 # for localization
 if environ.get("STREAMLINK_USE_PYCOUNTRY"):