Help for unbrick recovery (hboot 2.27)

Under hboot 2.27 (unlocking, s-on), I flashed a wrong 3rd recovery, so the official one is bricked, I can't upgrade the phone via OTA.

Any one can help this? many thanks,

my phone info from fashboot getvar

=====
roc Downloads$ ./fastboot-mac getvar all
INFOversion: 0.5
INFOversion-bootloader: 2.27.0000
INFOversion-baseband: U3.08.3507.26
INFOversion-cpld: None
INFOversion-microp: None
INFOversion-main: 2.30.1402.1
INFOversion-misc: PVT SHIP S-ON
INFOserialno: HC34WW901296
INFOimei: 355868050271585
INFOmeid: 00000000000000
INFOproduct: m7cdug
INFOplatform: HBOOT-8064
INFOmodelid: PN0771000
INFOcidnum: HTCCN703
INFObattery-status: good
INFObattery-voltage: 4150mV
INFOpartition-layout: Generic
INFOsecurity: on
INFObuild-mode: SHIP
INFOboot-mode: RUU
INFOcommitno-bootloader: dirty-d959c75800
INFOhbootpreupdate: 11
INFOgencheckpt: 0
all: Done!