message: small tweak to filter parser
diff: /* @flow */
  +const validDivisionCharRE = /[\w).+\-_$\]]/
  +
  export function parseFilters (exp: string): string {
  let inSingle = false
  let inDouble = false
  @@ -55,7 +57,7 @@ export function parseFilters (exp: string): string {
  p = exp.charAt(j)
  if (p !== ' ') break
  }
  - if (!p || !/[\w).\]\+\-\_$]/.test(p)) {
  + if (!p || !validDivisionCharRE.test(p)) {
  inRegex = true
  }
  }
  