Fix Qemu binary not set when adding appliance from template

gns3server/compute/qemu/qemu_vm.py

@@ -216,7 +216,7 @@ class QemuVM(BaseNode):
             if qemu_bin == "qemu":
                 self._platform = "i386"
             else:
-                self._platform = re.sub(r'^qemu-system-(.*)$', r'\1', qemu_bin, re.IGNORECASE)
+                self._platform = re.sub(r'^qemu-system-(\w+).*$', r'\1', qemu_bin, re.IGNORECASE)
         if self._platform.split(".")[0] not in QEMU_PLATFORMS:
             raise QemuError("Platform {} is unknown".format(self._platform))
         log.info('QEMU VM "{name}" [{id}] has set the QEMU path to {qemu_path}'.format(name=self._name,