nit: remove double space in deprecation warning (#4018)

diff --git a/src/cryptography/x509/general_name.py b/src/cryptography/x509/general_name.py
index 65ba75c..26f389a 100644
--- a/src/cryptography/x509/general_name.py
+++ b/src/cryptography/x509/general_name.py
@@ -59,7 +59,7 @@
                     "RFC822Name values should be passed as an A-label string. "
                     "This means unicode characters should be encoded via "
                     "idna. Support for passing unicode strings (aka U-label) "
-                    " will be removed in a future version.",
+                    "will be removed in a future version.",
                     utils.DeprecatedIn21,
                     stacklevel=2,
                 )
@@ -124,7 +124,7 @@
                     "DNSName values should be passed as an A-label string. "
                     "This means unicode characters should be encoded via "
                     "idna. Support for passing unicode strings (aka U-label) "
-                    " will be removed in a future version.",
+                    "will be removed in a future version.",
                     utils.DeprecatedIn21,
                     stacklevel=2,
                 )