bpo-35128: Fix spacing issues in warning.warn() messages. (GH-10268)

Lib/bz2.py

@@ -66,7 +66,7 @@ class BZ2File(_compression.BaseStream):
         self._mode = _MODE_CLOSED
 
         if buffering is not _sentinel:
-            warnings.warn("Use of 'buffering' argument is deprecated  and ignored"
+            warnings.warn("Use of 'buffering' argument is deprecated and ignored "
                           "since Python 3.0.",
                           DeprecationWarning,
                           stacklevel=2)

Lib/ftplib.py

@@ -732,7 +732,7 @@ else:
                                  "exclusive")
             if keyfile is not None or certfile is not None:
                 import warnings
-                warnings.warn("keyfile and certfile are deprecated, use a"
+                warnings.warn("keyfile and certfile are deprecated, use a "
                               "custom context instead", DeprecationWarning, 2)
             self.keyfile = keyfile
             self.certfile = certfile

Lib/imaplib.py

@@ -1277,7 +1277,7 @@ if HAVE_SSL:
                                  "exclusive")
             if keyfile is not None or certfile is not None:
                 import warnings
-                warnings.warn("keyfile and certfile are deprecated, use a"
+                warnings.warn("keyfile and certfile are deprecated, use a "
                               "custom ssl_context instead", DeprecationWarning, 2)
             self.keyfile = keyfile
             self.certfile = certfile

Lib/poplib.py

@@ -436,7 +436,7 @@ if HAVE_SSL:
                                  "exclusive")
             if keyfile is not None or certfile is not None:
                 import warnings
-                warnings.warn("keyfile and certfile are deprecated, use a"
+                warnings.warn("keyfile and certfile are deprecated, use a "
                               "custom context instead", DeprecationWarning, 2)
             self.keyfile = keyfile
             self.certfile = certfile

Lib/smtplib.py

@@ -764,7 +764,7 @@ class SMTP:
                                  "exclusive")
             if keyfile is not None or certfile is not None:
                 import warnings
-                warnings.warn("keyfile and certfile are deprecated, use a"
+                warnings.warn("keyfile and certfile are deprecated, use a "
                               "custom context instead", DeprecationWarning, 2)
             if context is None:
                 context = ssl._create_stdlib_context(certfile=certfile,
@@ -1021,7 +1021,7 @@ if _have_ssl:
                                  "exclusive")
             if keyfile is not None or certfile is not None:
                 import warnings
-                warnings.warn("keyfile and certfile are deprecated, use a"
+                warnings.warn("keyfile and certfile are deprecated, use a "
                               "custom context instead", DeprecationWarning, 2)
             self.keyfile = keyfile
             self.certfile = certfile