try if super is installed

pythonrewrite/bin2/CryptoBox.py

@@ -139,14 +139,17 @@ class CryptoBox:
 		except IOError:
 			self.log.error("Could not open %s for writing!" % os.devnull)
 			sys.exit(1)
-		proc = subprocess.Popen(
-			shell = False,
-			stdout = devnull,
-			stderr = devnull,
-			args = [
-				self.cbxPrefs["Programs"]["super"],
-				self.cbxPrefs["Programs"]["CryptoBoxRootActions"],
-				"check"])
+		try:
+			proc = subprocess.Popen(
+				shell = False,
+				stdout = devnull,
+				stderr = devnull,
+				args = [ self.cbxPrefs["Programs"]["super"],
+							self.cbxPrefs["Programs"]["CryptoBoxRootActions"],
+							"check"])
+		except OSError:
+			self.log.error("could not find: %s" % self.cbxPrefs["Programs"]["super"])
+			sys.exit(1)
 		proc.wait()
 		if proc.returncode != 0:
 			self.log.error("Could not call CryptoBoxRootActions by 'super' - maybe you did not add the appropriate line to /etc/super.tab?")