Fix an error message (the debugger was invalid, not the target.)

llvm-svn: 251720
diff --git a/lldb/source/API/SBDebugger.cpp b/lldb/source/API/SBDebugger.cpp
index fca43d6..53785cd 100644
--- a/lldb/source/API/SBDebugger.cpp
+++ b/lldb/source/API/SBDebugger.cpp
@@ -638,7 +638,7 @@
     }
     else
     {
-        sb_error.SetErrorString("invalid target");
+        sb_error.SetErrorString("invalid debugger");
     }
 
     Log *log(GetLogIfAllCategoriesSet (LIBLLDB_LOG_API));