chore: Optimize condition

Author: tony

src/tmuxp/util.py

@@ -53,16 +53,10 @@ def run_before_script(
         return_code = proc.poll()
 
         # Read one line from stdout, if available
-        if proc.stdout:
-            line_out = proc.stdout.readline()
-        else:
-            line_out = ""
+        line_out = proc.stdout.readline() if proc.stdout else ""
 
         # Read one line from stderr, if available
-        if proc.stderr:
-            line_err = proc.stderr.readline()
-        else:
-            line_err = ""
+        line_err = proc.stderr.readline() if proc.stderr else ""
 
         if line_out:
             out_buffer.append(line_out)