Typo fix in extrabackup.cc and innobackupex.cc

Thanks to @shinguz for helping with this.
This a backport commit from 10.7

extra/mariabackup/innobackupex.cc

@@ -307,7 +307,7 @@ static struct my_option ibx_long_options[] =
 	{"force-non-empty-directories", OPT_FORCE_NON_EMPTY_DIRS, "This "
 	 "option, when specified, makes --copy-back or --move-back transfer "
 	 "files to non-empty directories. Note that no existing files will be "
-	 "overwritten. If --copy-back or --nove-back has to copy a file from "
+	 "overwritten. If --copy-back or --move-back has to copy a file from "
 	 "the backup directory which already exists in the destination "
 	 "directory, it will still fail with an error.",
 	 (uchar *) &opt_ibx_force_non_empty_dirs,

extra/mariabackup/xtrabackup.cc

@@ -1281,7 +1281,7 @@ struct my_option xb_client_options[]= {
      "This "
      "option, when specified, makes --copy-back or --move-back transfer "
      "files to non-empty directories. Note that no existing files will be "
-     "overwritten. If --copy-back or --nove-back has to copy a file from "
+     "overwritten. If --copy-back or --move-back has to copy a file from "
      "the backup directory which already exists in the destination "
      "directory, it will still fail with an error.",
      (uchar *) &opt_force_non_empty_dirs, (uchar *) &opt_force_non_empty_dirs,