Update tokrules.py

[OpenSCAD] fix parser error for numbers with positive exponent >= 6
see forum: https://forum.freecadweb.org/viewtopic.php?f=3&t=54044

src/Mod/OpenSCAD/tokrules.py

@@ -86,7 +86,7 @@ tokens = reserved + (
 
 # Regular expression rules for simple tokens
 t_WORD    = r'[$]?[a-zA-Z_]+[0-9]*'
-t_NUMBER  = r'[-]?[0-9]*[\.]*[0-9]+([eE]-?[0-9]+)*'
+t_NUMBER  = r'[-]?[0-9]*[\.]*[0-9]+([eE][+-]?[0-9]+)*'
 t_LPAREN  = r'\('
 t_RPAREN  = r'\)'
 t_OBRACE  = r'{'