DocstringMetadata.py: Remove unneeded space

Ensures that there is no unneeded space after opening parenthesis
while prompting a user for required setting.

Fixes coala#3164

coalib/settings/DocstringMetadata.py

@@ -57,7 +57,7 @@ def from_docstring(cls, docstring):
 
             def concat_doc_parts(old: str, new: str):
                 if new != '' and not old.endswith('\n'):
-                    return old + ' ' + new
+                    return (old + ' ' + new).strip()
 
                 return old + (new if new != '' else '\n')
 

tests/settings/DocstringMetadataTest.py

@@ -1,6 +1,7 @@
 import unittest
 
 from coalib.settings.DocstringMetadata import DocstringMetadata
+from collections import OrderedDict
 
 
 class DocstringMetadataTest(unittest.TestCase):
@@ -54,6 +55,25 @@ def test_str(self):
 
         self.assertEqual(str(uut), 'Description of something with params.')
 
+    def test_unneeded_docstring_space(self):
+        uut = DocstringMetadata.from_docstring(
+            """
+            This is a description about some bear which does some amazing
+            things. This is a multiline description for this testcase.
+
+            :param language:
+                The programming language.
+            :param coalang_dir:
+                External directory for coalang file.
+            """)
+
+        expected_output = OrderedDict([('language', ('The programming '
+                                                     'language.')),
+                                       ('coalang_dir', ('External directory '
+                                                        'for coalang file.'))])
+
+        self.assertEqual(uut.param_dict, expected_output)
+
     def check_from_docstring_dataset(self,
                                      docstring,
                                      desc='',