PEP 458: Fix figure reference and typo (#1326)

In secure-systems-lab/peps#73 Figure 2 became Figure 1. This change
fixes a missed reference update.

It also removes a stray "and".

Signed-off-by: Lukas Puehringer <lukas.puehringer@nyu.edu>

pep-0458.txt

@@ -625,7 +625,7 @@ implementation (Nov 7 2019), summarized in Tables 2-3, PyPI SHOULD
 split all targets in the *bins* role by delegating them to 16,384
 *bin-n* roles (see C10 in Table 2). Each *bin-n* role would sign
 for the PyPI targets whose SHA2-512 hashes fall into that bin
-(see and Figure 2 and `Consistent Snapshots`_). It was found
+(see Figure 1 and `Consistent Snapshots`_). It was found
 that this number of bins would result in a 5-9% metadata overhead
 (relative to the average size of downloaded distribution files; see V13 and
 V15 in Table 3) for returning users, and a 69% overhead for new