Dpi unaware placement bug (#2121)

Fix for bug when placing dpi unaware window such as Notepad++ in left of right part of monitor. In that application gap of about 7px was left or right.
This fixes only single-monitor scenario
It skips correction for dpi unaware window that leaves a gap

src/common/monitors.cpp

@@ -38,6 +38,11 @@ std::vector<MonitorInfo> MonitorInfo::GetMonitors(bool include_toolbar)
     return monitors;
 }
 
+int MonitorInfo::GetMonitorsCount()
+{
+    return GetMonitors(true).size();
+}
+
 static BOOL CALLBACK get_primary_display_enum_cb(HMONITOR monitor, HDC hdc, LPRECT rect, LPARAM data)
 {
     MONITORINFOEX monitor_info;

src/common/monitors.h

@@ -32,6 +32,7 @@ struct MonitorInfo : ScreenSize
 
     // Returns monitor rects ordered from left to right
     static std::vector<MonitorInfo> GetMonitors(bool include_toolbar);
+    static int GetMonitorsCount();
     // Return primary display
     static MonitorInfo GetPrimaryMonitor();
     // Return monitor on which hwnd window is displayed