[Minor] Relax content type params values parser

Issue: #1682

src/ragel/content_type.rl

@@ -14,7 +14,7 @@
                     (((FWS? qcontent)* FWS?) >Quoted_Str_Start %Quoted_Str_End)
                   DQUOTE) CFWS?;
   token = 0x21..0x27 | 0x2a..0x2b | 0x2c..0x2e | 0x30..0x39 | 0x41..0x5a | 0x5e..0x7e;
-  value = (quoted_string | (token -- '"' | 0x3d)+) >Param_Value_Start %Param_Value_End;
+  value = (quoted_string | (token | 0x3d)+) >Param_Value_Start %Param_Value_End;
   attribute = (token+) >Param_Name_Start %Param_Name_End;
   parameter = CFWS? attribute FWS? "=" FWS? value CFWS?;