Debugger: Force English debugger output

So that ptrace output can be recognized.

Fixes: QTCREATORBUG-26384
Change-Id: Ibd9456963a5379c333782287754bf9aed4235dc4
Reviewed-by: Christian Stenger <christian.stenger@qt.io>

src/plugins/debugger/gdb/gdbengine.cpp

@@ -3846,6 +3846,7 @@ void GdbEngine::setupEngine()
         gdbCommand.addArg("-n");
 
     Environment gdbEnv = rp.debugger.environment;
+    gdbEnv.setupEnglishOutput();
     if (rp.runAsRoot) {
         CommandLine wrapped("sudo", {"-A"});
         wrapped.addCommandLineAsArgs(gdbCommand);