BuildSteps: Fix a number of crashes

Fix crashes due to activeProjectConfigurationChanged signal sending
a nullptr.

Uses the same fix as QTCREATORBUG-18865, but in more places:-)

Task-number: QTCREATORBUG-18866
Change-Id: Ic71af5ed26b2a44339f0c687f3f46bfdf62c2489
Reviewed-by: Tim Jenssen <tim.jenssen@qt.io>

src/plugins/autotoolsprojectmanager/makestep.cpp

@@ -242,7 +242,7 @@ MakeStepConfigWidget::MakeStepConfigWidget(MakeStep *makeStep) :
     });
     connect(makeStep->project(), &Project::activeProjectConfigurationChanged,
             this, [this](ProjectConfiguration *pc) {
-        if (pc->isActive())
+        if (pc && pc->isActive())
             updateDetails();
     });
 }

src/plugins/genericprojectmanager/genericmakestep.cpp

@@ -258,7 +258,7 @@ GenericMakeStepConfigWidget::GenericMakeStepConfigWidget(GenericMakeStep *makeSt
     });
     connect(pro, &Project::activeProjectConfigurationChanged,
             this, [this](ProjectConfiguration *pc) {
-        if (pc->isActive()) {
+        if (pc && pc->isActive()) {
             updateMakeOverrideLabel();
             updateDetails();
         }

src/plugins/ios/iosbuildstep.cpp

@@ -266,7 +266,7 @@ IosBuildStepConfigWidget::IosBuildStepConfigWidget(IosBuildStep *buildStep)
     });
     connect(pro, &Project::activeProjectConfigurationChanged,
             this, [this](ProjectConfiguration *pc) {
-        if (pc->isActive())
+        if (pc && pc->isActive())
             updateDetails();
     });
 }

src/plugins/ios/iosdsymbuildstep.cpp

@@ -266,7 +266,7 @@ IosPresetBuildStepConfigWidget::IosPresetBuildStepConfigWidget(IosPresetBuildSte
     });
     connect(pro, &Project::activeProjectConfigurationChanged,
             this, [this](ProjectConfiguration *pc) {
-        if (pc->isActive())
+        if (pc && pc->isActive())
             updateDetails();
     });
 }

src/plugins/qbsprojectmanager/qbsproject.cpp

@@ -146,7 +146,7 @@ QbsProject::QbsProject(const FileName &fileName) :
     });
     connect(this, &Project::activeProjectConfigurationChanged,
             this, [this](ProjectConfiguration *pc) {
-        if (pc->isActive())
+        if (pc && pc->isActive())
             startParsing();
     });
 

src/plugins/qmakeprojectmanager/qmakeprojectconfigwidget.cpp

@@ -104,7 +104,7 @@ QmakeProjectConfigWidget::QmakeProjectConfigWidget(QmakeBuildConfiguration *bc)
     });
     connect(project, &Project::activeProjectConfigurationChanged,
             this, [this](ProjectConfiguration *pc) {
-        if (pc->isActive())
+        if (pc && pc->isActive())
             environmentChanged();
     });
     connect(project, &QmakeProject::buildDirectoryInitialized,