[issue-788] fix tag-value parser to allow NONE and NOASSERTION for package source info as they are valid strings

Signed-off-by: Meret Behrens <[email protected]>

# fixes 788

Author: meretp

src/spdx_tools/spdx/parser/tagvalue/parser.py

@@ -219,7 +219,8 @@ def p_text(self, p):
     @grammar_rule(
         "text_or_line : LINE\n line_or_no_assertion : LINE\nline_or_no_assertion_or_none : text_or_line\n"
         "text_or_line_including_no_assertion : text_or_line\ntext_or_line_including_no_assertion : NO_ASSERTION\n"
-        "text_or_line_including_no_assertion : NONE")
+        "text_or_line_including_no_assertion : NONE"
+    )
     def p_line(self, p):
         p[0] = p[1]