Delete the space that comes before _?= in the uninstaller $CMDLINE

git-svn-id: https://svn.code.sf.net/p/nsis/code/NSIS/trunk@2045 212acab6-be3b-0410-9dea-997c60f758d6

Source/exehead/Main.c

@@ -278,7 +278,7 @@ int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInst,LPSTR lpszCmdParam,
 
     if (p >= cmdline)
     {
-      p[0]=0; // terminate on the _?=
+      *(p-1)=0; // terminate before the " _?="
       p+=3; // skip over _?=
       if (is_valid_instpath(p))
       {