Some clients even send plain : in their requests

scan_urlencoded_query.c

@@ -11,11 +11,11 @@
          mark          = "-" | "_" | "." | "!" | "~" | "*" | "'" | "(" | ")"
    we add '%' to the matrix to not stop at encoded chars.
    After losing too many requests to being too strict, add the following characters to reserved matrix
-         relax         = "+" | "," | "/" | ";" | "<" | ">"
+         relax         = "+" | "," | "/" | ";" | "<" | ">" | ":"
 
 static const unsigned char reserved_matrix_strict[] = { 0xA2, 0x67, 0xFF, 0x03, 0xFE, 0xFF, 0xFF, 0x87, 0xFE, 0xFF, 0xFF, 0x47};
 */
-static const unsigned char reserved_matrix[] = { 0xA2, 0xFF, 0xFF, 0x5B, 0xFE, 0xFF, 0xFF, 0x87, 0xFE, 0xFF, 0xFF, 0x47};
+static const unsigned char reserved_matrix[] = { 0xA2, 0xFF, 0xFF, 0x5F, 0xFE, 0xFF, 0xFF, 0x87, 0xFE, 0xFF, 0xFF, 0x47};
 
 static int is_unreserved( unsigned char c ) {
   if( ( c <= 32 ) || ( c >= 127 ) ) return 0; return 1&(reserved_matrix[(c-32)>>3]>>(c&7));