Fix issues launching fsck via terminal on Linux (#1086)

Currently on a system without xterm or konsole (like fresh
Ubuntu install) the fsck check will not launch. Added
gnome-terminal as an alternative and fixed an issue where
konsole will always error out as --title and --caption are
no longer valid arguments.

Previously the error message was simply "xterm not found", so
new LangString LINUX_EX2MSG_TERMINALNOTFOUND was added to let the
user knows which programs they need to get the feature working.

Translations/Language.ko.xml

@@ -1569,6 +1569,7 @@
     <entry lang="ko" key="CANT_INSTALL_WITH_EXE_OVER_MSI">VeraCrypt가 MSI 패키지(.msi)로 설치되어 표준 설치 프로그램으로 업데이트 할 수 없습니다.\n\nMSI 패키지를 사용하여 VeraCrypt를 업데이트하십시오.</entry>
     <entry lang="ko" key="IDC_USE_ALL_FREE_SPACE">사용 가능한 모든 여유 공간 사용</entry>
     <entry lang="ko" key="SYS_ENCRYPTION_UPGRADE_UNSUPPORTED_ALGORITHM">시스템 파티션/드라이브가 더 이상 지원되지 않는 알고리즘으로 암호화되었기 때문에 VeraCrypt를 업데이트할 수 없습니다.\nVeraCrypt를 업데이트 하기 전에 시스템 암호를 해독한 다음 다시 암호화하십시오.</entry>
+    <entry lang="en" key="LINUX_EX2MSG_TERMINALNOTFOUND">Supported terminal application could not be found, you need either xterm, konsole or gnome-terminal (with dbus-x11).</entry>
   </localization>
   <xs:schema attributeFormDefault="unqualified" elementFormDefault="qualified" xmlns:xs="http://www.w3.org/2001/XMLSchema">
     <xs:element name="VeraCrypt">