libgmpxx4 from home:ecsos project

需要 openSUSE Slowroll ，用 root 執行：

zypper addrepo https://download.opensuse.org/repositories/home:ecsos/openSUSE_Slowroll/home:ecsos.repo
zypper refresh
zypper install libgmpxx4

需要 16.0 ，用 root 執行：

zypper addrepo https://download.opensuse.org/repositories/home:ecsos/16.0/home:ecsos.repo
zypper refresh
zypper install libgmpxx4

需要 15.6 ，用 root 執行：

zypper addrepo https://download.opensuse.org/repositories/home:ecsos/15.6/home:ecsos.repo
zypper refresh
zypper install libgmpxx4