dataset: try to finally fix flair dependency

germeval2014.py

@@ -20,6 +20,12 @@ import json
 
 import datasets
 
+try:
+    import flair
+except:
+    import os
+    os.system('pip3 install git+https://github.com/flairNLP/flair.git')
+
 
 _CITATION = """\
 @inproceedings{benikova14:_germev_named_entit_recog_shared_task,
@@ -179,12 +185,7 @@ class GermEval2014(datasets.GeneratorBasedBuilder):
         )
 
     def _split_generators(self, dl_manager):
-        try:
-            import flair
-        except:
-            import os
-            os.system('pip3 install git+https://github.com/flairNLP/flair.git')
-
+        import flair
         from flair.datasets import NER_GERMAN_GERMEVAL
         corpus = NER_GERMAN_GERMEVAL()