FutureWarning for .loc[list-of-labels] with missing labels provides wrong URL
#### Code Sample, a copy-pastable example if possible

```
In [2]: s = pd.Series(['foo', 'bar', 'baz'])

In [3]: s.loc[[2,3]]
FutureWarning:
Passing list-likes to .loc or [] with any missing label will raise
KeyError in the future, you can use .reindex() as an alternative.

See the documentation here:
http://pandas.pydata.org/pandas-docs/stable/indexing.html#deprecate-loc-reindex-listlike
  if __name__ == '__main__':
Out[3]:
2    baz
3    NaN
dtype: object
```
#### Problem description
The URL in the deprecation warning has the wrong section name (#deprecate-loc-reindex-listlike), so the user isn't redirected to the relevant section.

#### Expected Output
I'd expect the URL to be link to have the correct section name (#indexing-deprecate-loc-reindex-listlike) or change the section name so it matches the link.

#### Output of ``pd.show_versions()``

<details>

INSTALLED VERSIONS
------------------
commit: 78147e9c84fb55a67af382a2d3a090e6b0828532
python: 3.6.1.final.0
python-bits: 64
OS: Windows
OS-release: 10
machine: AMD64
processor: Intel64 Family 6 Model 78 Stepping 3, GenuineIntel
byteorder: little
LC_ALL: None
LANG: None
LOCALE: None.None

pandas: 0.23.0.dev0+81.g78147e9
pytest: 3.1.2
pip: 9.0.1
setuptools: 27.2.0
Cython: 0.25.2
numpy: 1.13.3
scipy: 1.0.0
pyarrow: 0.6.0
xarray: 0.9.6
IPython: 6.1.0
sphinx: 1.5.6
patsy: 0.4.1
dateutil: 2.6.0
pytz: 2017.2
blosc: None
bottleneck: None
tables: 3.4.2
numexpr: 2.6.4
feather: 0.4.0
matplotlib: 2.0.2
openpyxl: 2.4.8
xlrd: 1.1.0
xlwt: 1.3.0
xlsxwriter: 0.9.8
lxml: 3.8.0
bs4: None
html5lib: 0.999
sqlalchemy: 1.1.13
pymysql: None
psycopg2: None
jinja2: 2.9.6
s3fs: None
fastparquet: 0.1.0
pandas_gbq: None
pandas_datareader: None

</details>

  