fixed some flake8 issues in multi_datasets.py

Author: axel-lauer

esmvaltool/diag_scripts/monitor/multi_datasets.py

@@ -69,19 +69,19 @@
       needs to be 2D with dimensions `time`, `latitude`/`longitude`.
     - Benchmarking plot annual cycles (``benchmarking_annual_cycle``)
       Same as plot type ``annual_cycle`` but including the range of metric
-      results from an ensemble of models as shading. 
+      results from an ensemble of models as shading.
     - Benchmarking box plots (``benchmarking_boxplot``)
       Box plots showing the metric results for given variables from a given
       model and the range from the first quartile to the third quartile, the
       median, and minimum and maximum values (excluding the outliers) from
-      an ensemble of models for comparison. 
+      an ensemble of models for comparison.
     - Benchmarking plot diurnal cycles (``benchmarking_diurnal_cycle``)
       Same as plot type ``diurnal_cycle`` but including range of metric results
       from an ensemble of models as shading.
     - Benchmarking map plots (``benchmarking_map``)
       Same as plot type ``map`` but with stippled areas masking grid cells
-      where the selected metric is smaller than the 90% percentile of corresponding
-      values from an ensemble of models used for comparison.
+      where the selected metric is smaller than the 90% percentile of
+      corresponding values from an ensemble of models used for comparison.
     - Benchmarking plot time series (``benchmarking_timeseries``)
       Same as plot type ``timeseries`` but including the range of metric
       results from an ensemble of models as shading.
@@ -655,7 +655,7 @@
     '{short_name}'``, ``xlim: [0, 5]``.
 var_order: str (list), optional
     Optional list of strings containing variable names to define the order of
-    the variables plotted. 
+    the variables plotted.
 label: str, optional
     Facet_used_for_labels.
 fontsize: int, optional (default: 10)