add temporary limitation for managers subcommands

src/main.rs

@@ -40,6 +40,10 @@ fn main() {
             link,
             no_link,
         } => {
+            if current_task_info.is_some() {
+                panic!("You can change priority only when you don't have an active task, yet");
+            }
+
             if idx == 0 || idx > tasks.len() {
                 panic!("invalid index");
             }
@@ -61,6 +65,10 @@ fn main() {
             println!("changed");
         }
         cli::SubCommand::Remove { idx } => {
+            if current_task_info.is_some() {
+                panic!("You can change priority only when you don't have an active task, yet");
+            }
+
             if idx == 0 || idx > tasks.len() {
                 panic!("invalid index");
             }
@@ -110,6 +118,10 @@ fn main() {
             idx: target_idx,
             priority,
         } => {
+            if current_task_info.is_some() {
+                panic!("You can change priority only when you don't have an active task, yet");
+            }
+
             if target_idx == 0 || target_idx > tasks.len() {
                 panic!("invalid index");
             }