[Tts-project] Bug#935489: festival: server mode does not respect voice_default

[ghost]

Package: festival
Version: 1:2.5.0-3
Severity: normal

Dear Maintainer,

    I added the following line to /etc/festival.scm

        (set! voice_default 'voice_cmu_us_slt_arctic_hts)

    Now `echo hello | festival --tts` is using the new default. However,
    if I start a `festival --server` and access it through `spd-say`,
    kal_diphone is used instead.


-- System Information:
Debian Release: 10.0
  APT prefers stable-updates
  APT policy: (900, 'stable-updates'), (900, 'stable-debug'), (900, 'stable')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 4.19.0-5-amd64 (SMP w/2 CPU cores)
Kernel taint flags: TAINT_OOT_MODULE, TAINT_UNSIGNED_MODULE
Locale: LANG=zh_CN.UTF-8, LC_CTYPE=zh_CN.UTF-8 (charmap=UTF-8), LANGUAGE=zh_CN:zh (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled

Versions of packages festival depends on:
ii  adduser        3.118
ii  alsa-utils     1.1.8-2
ii  libc6          2.28-10
ii  libestools2.5  1:2.5.0-5
ii  libgcc1        1:8.3.0-6
ii  libgomp1       8.3.0-6
ii  libstdc++6     8.3.0-6
ii  lsb-base       10.2019051400
ii  sgml-base      1.29

Versions of packages festival recommends:
ii  festvox-kallpc16k [festival-voice]   2.4-1
ii  festvox-us-slt-hts [festival-voice]  0.2010.10.25-2

Versions of packages festival suggests:
ii  festival-freebsoft-utils  0.10-7
pn  pidgin-festival           <none>

-- Configuration Files:
/etc/festival.scm changed [not included]

-- no debconf information