Drop Qt4 related settings from QMake project

macxconf.pri

@@ -11,9 +11,6 @@ exists($$OUT_PWD/../conf.pri) {
 
 LIBS += -framework Carbon -framework IOKit
 
-# C++11 support
-lessThan(QT_MAJOR_VERSION, 5): QMAKE_CXXFLAGS += -std=c++11
-
 QT_LANG_PATH = ../dist/qt-translations
 DIST_PATH = ../dist/mac
 

os2conf.pri

@@ -1,6 +1,3 @@
-# C++11 support
-lessThan(QT_MAJOR_VERSION, 5): QMAKE_CXXFLAGS += -std=c++11
-
 exists(conf.pri) {
     # to the conf.pri goes all system dependent stuff
     include(conf.pri)

qm_gen.pri

@@ -1,13 +1,10 @@
 TS_IN = $$fromfile(src/src.pro,TRANSLATIONS)
 TS_IN_NOEXT = $$replace(TS_IN,".ts","")
-             
+
 isEmpty(QMAKE_LRELEASE) {
     win32|os2:QMAKE_LRELEASE = $$[QT_INSTALL_BINS]\\lrelease.exe
     else:QMAKE_LRELEASE = $$[QT_INSTALL_BINS]/lrelease
     unix {
-      equals(QT_MAJOR_VERSION, 4) {
-        !exists($$QMAKE_LRELEASE) { QMAKE_LRELEASE = lrelease-qt4 }
-      } 
       equals(QT_MAJOR_VERSION, 5) {
         !exists($$QMAKE_LRELEASE) { QMAKE_LRELEASE = lrelease-qt5 }
       }

src/src.pro

@@ -6,8 +6,6 @@ CONFIG += qt thread silent
 CONFIG += c++11
 DEFINES += BOOST_NO_CXX11_RVALUE_REFERENCES
 
-lessThan(QT_MAJOR_VERSION, 5): DEFINES += QStringLiteral=QLatin1String
-
 # Windows specific configuration
 win32: include(../winconf.pri)
 
@@ -25,8 +23,7 @@ nogui {
     DEFINES += DISABLE_GUI
     TARGET = qbittorrent-nox
 } else {
-    QT += xml
-    greaterThan(QT_MAJOR_VERSION, 4): QT += concurrent widgets
+    QT += xml concurrent widgets
     CONFIG(static) {
         DEFINES += QBT_STATIC_QT
         QTPLUGIN += qico

unixconf.pri

@@ -9,9 +9,6 @@ exists($$OUT_PWD/../conf.pri) {
     include(conf.pri)
 }
 
-# C++11 support
-lessThan(QT_MAJOR_VERSION, 5): QMAKE_CXXFLAGS += -std=c++11
-
 # COMPILATION SPECIFIC
 !nogui:dbus: QT += dbus
 

winconf-mingw.pri

@@ -1,6 +1,3 @@
-# C++11 support
-lessThan(QT_MAJOR_VERSION, 5): QMAKE_CXXFLAGS += -std=gnu++11
-
 strace_win{
   contains(QMAKE_HOST.arch, x86) {
     # i686 arch requires frame pointer preservation