Fix spelling errors in messages shown to users

Reported-by: Jens Schleusener <Jens.Schleusener@fossies.org>
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

contrib/svn-fe/svnrdump_sim.py

@@ -54,7 +54,7 @@ if __name__ == "__main__":
         print("usage: %s dump URL -rLOWER:UPPER")
         sys.exit(1)
     if not sys.argv[1] == 'dump':
-        raise NotImplementedError('only "dump" is suppported.')
+        raise NotImplementedError('only "dump" is supported.')
     url = sys.argv[2]
     r = ('0', 'HEAD')
     if len(sys.argv) == 4 and sys.argv[3][0:2] == '-r':