package names different in SLES 15 - please fix requires.spec

[christophvw]

Please fix https://github.com/ONLYOFFICE/document-server-package/blob/master/rpm/requires.spec for SLES 15.

package liberation-mono-fonts is liberation-fonts in SLES 15
package msttcore-fonts-installer is fetchmsttfonts in SLES 15

https://scc.suse.com/packages?name=SUSE%20Linux%20Enterprise%20Server&version=15.6&arch=x86_64&query=liberation-fonts
https://scc.suse.com/packages?name=SUSE%20Linux%20Enterprise%20Server&version=15.6&arch=x86_64&query=fetchmsttfonts

Starting with rpm-4.13, RPM is able to process boolean expressions in all dependencies (Requires, Recommends, Suggests, Supplements, Enhances, Conflicts). Boolean Expressions are always enclosed with parenthesis.
see https://rpm-software-management.github.io/rpm/manual/boolean_dependencies.html

current

Requires: nginx >= 1.3.13, postgresql >= 9.1, curl, wget, libstdc++ >= 4.8.4, libcurl, libxml2, zlib, libXScrnSaver, atk, gtk3, xorg-x11-server-Xvfb, libXtst, alsa-lib, pwgen, libselinux-utils, liberation-mono-fonts, logrotate, ca-certificates, msttcore-fonts-installer, openssl

should be:

Requires: nginx >= 1.3.13, postgresql >= 9.1, curl, wget, libstdc++ >= 4.8.4, libcurl, libxml2, zlib, libXScrnSaver, atk, gtk3, xorg-x11-server-Xvfb, libXtst, alsa-lib, pwgen, libselinux-utils, (liberation-mono-fonts or liberation-fonts), logrotate, ca-certificates, (msttcore-fonts-installer or fetchmsttfonts), openssl