Identify Linux riscv64 as unix

Author: senekor

static/scripts/tools-install.js

@@ -29,6 +29,7 @@ function detect_platform() {
     if (navigator.platform == "Linux ppc64") {os = "unix";}
     if (navigator.platform == "Linux mips") {os = "unix";}
     if (navigator.platform == "Linux mips64") {os = "unix";}
+    if (navigator.platform == "Linux riscv64") {os = "unix";}
     if (navigator.platform == "Mac") {os = "unix";}
     if (navigator.platform == "Win32") {os = "win";}
     if (navigator.platform == "FreeBSD x86_64") {os = "unix";}