UNSAFE -> WEAK in RSA key environment variable

.travis.yml

@@ -9,7 +9,7 @@ go:
 env:
   global:
     - BUILD_DEPTYPE=gomod
-    - LIBP2P_ALLOW_UNSAFE_RSA_KEYS=1
+    - LIBP2P_ALLOW_WEAK_RSA_KEYS=1
   matrix:
     - GOTFLAGS="-race"
     - GOTFLAGS="-race -tags=openssl"

crypto/rsa_common.go

@@ -8,7 +8,7 @@ import (
 // UnsafeRsaKeyEnv is an environment variable which, when set, lowers the
 // minimum required bits of RSA keys to 512. This should be used exclusively in
 // test situations.
-const UnsafeRsaKeyEnv = "LIBP2P_ALLOW_UNSAFE_RSA_KEYS"
+const UnsafeRsaKeyEnv = "LIBP2P_ALLOW_WEAK_RSA_KEYS"
 
 var MinRsaKeyBits = 2048