Update lxc_utils.py

should fix [this issue](#16)

lxc_autoscale/lxc_utils.py

@@ -193,7 +193,17 @@ def get_total_memory():
     Returns:
         int: The amount of available memory in MB.
     """
-    total_memory = int(run_command("free -m | awk '/Mem:/ {print $2}'"))
+    try:
+        command_output = run_command("free -m | awk '/^MemTotal:/ {print $2}')")
+        if not command_output:
+            logging.warning("Failed to retrieve total memory. Defaulting to 0MB.")
+            total_memory = 0
+        else:
+            total_memory = int(command_output.strip())
+    except (ValueError, subprocess.CalledProcessError) as e:
+        logging.error(f"Failed to retrieve total memory: {e}")
+        total_memory = 0
+
     available_memory = max(0, total_memory - DEFAULTS['reserve_memory_mb'])
     logging.debug(
         f"Total memory: {total_memory}MB, Reserved memory: {DEFAULTS['reserve_memory_mb']}MB, "