Minor construction fix (-1.0 is correct "disabled" value for TextWrapPos, didn't have any incidence anyway)

imgui.cpp

@@ -1179,7 +1179,7 @@ struct ImGuiDrawContext
         ItemWidth = 0.0f;
         ButtonRepeat = false;
         AllowKeyboardFocus = true;
-        TextWrapPos = 1.0f;
+        TextWrapPos = -1.0f;
         ColorEditMode = ImGuiColorEditMode_RGB;
         memset(StackSizesBackup, 0, sizeof(StackSizesBackup));