improve formatter configuration (openapi-processor/openapi-processor-spring#331)

Author: hauner

openapi-processor-core/src/main/resources/formatter.properties

@@ -8,7 +8,7 @@ org.eclipse.jdt.core.formatter.alignment_for_enum_constants = 49
 org.eclipse.jdt.core.formatter.comment.format_javadoc_comments = true
 org.eclipse.jdt.core.formatter.comment.insert_new_line_for_parameter = do not insert
 org.eclipse.jdt.core.formatter.comment.clear_blank_lines_in_javadoc_comment = true
-
+org.eclipse.jdt.core.formatter.insert_new_line_at_end_of_file_if_missing = insert
 org.eclipse.jdt.core.formatter.alignment_for_record_components = 52
 org.eclipse.jdt.core.formatter.keep_record_declaration_on_one_line = one_line_if_empty
 org.eclipse.jdt.core.formatter.parentheses_positions_in_record_declaration = separate_lines_if_wrapped