tasks #7096: fix unicode error message

Change-Id: Icb3c691ae63263020f270e89a47ed98043b58e6c
tasks #7097: add feedback when user does not choose search type

Change-Id: I92beb94293e08569cb5e7c377ffdf6471e12d8d0
tasks #7099: keep type of search and keywords after entering invalid keywords

Change-Id: I2062cfa867d93e5c1f1e2d261723ddb3e62736d2
Merge commit 'refs/changes/77/2677/2' of ssh://gerrit.tuleap.net:29418/tuleap into stable

* ssh://gerrit.tuleap.net:29418/tuleap:
  tasks #7099: keep type of search and keywords after entering invalid keywords
  tasks #7097: add feedback when user does not choose search type
  tasks #7096: fix unicode error message
This is Tuleap 7.1.99.58

Change-Id: I9862251faebea3be65a013bb30749c8fab80b2d2