Adapt plist_from_memory() call sites in upstream_repo for libplist >= 2.7.

libplist 2.7 added a fourth out-parameter (plist_format_t *format) to
plist_from_memory. The vendored AltSign and AltServer sources from
rileytestut/AltServer-Windows pre-date this signature change. Distro
builds linking against the system libplist fail with "no matching
function for call to 'plist_from_memory'".

Pass NULL for the new format argument at each call site; the call
remains source-compatible with libplist 2.7 and newer. Older bundled
libplist builds are no longer relevant for this overlay since the
ebuild now requires the system libplist via pkg-config.

--- a/upstream_repo/AltSign/Application.cpp
+++ b/upstream_repo/AltSign/Application.cpp
@@ -68,7 +68,7 @@
 	auto plistData = readFile(path.string().c_str());
 
     plist_t plist = nullptr;
-    plist_from_memory((const char *)plistData.data(), (int)plistData.size(), &plist);
+    plist_from_memory((const char *)plistData.data(), (int)plistData.size(), &plist, NULL);
     if (plist == nullptr)
     {
         throw SignError(SignErrorCode::InvalidApp);
@@ -197,7 +197,7 @@
 		auto rawEntitlements = this->entitlementsString();
 
 		plist_t plist = nullptr;
-		plist_from_memory((const char*)rawEntitlements.data(), (int)rawEntitlements.size(), &plist);
+		plist_from_memory((const char*)rawEntitlements.data(), (int)rawEntitlements.size(), &plist, NULL);
 
 		if (plist != nullptr)
 		{
--- a/upstream_repo/AltSign/ProvisioningProfile.cpp
+++ b/upstream_repo/AltSign/ProvisioningProfile.cpp
@@ -279,7 +279,7 @@
     pointer = advanceToNextItem(pointer);
     
     plist_t parsedPlist = nullptr;
-    plist_from_memory((const char *)pointer, (unsigned int)length, &parsedPlist);
+    plist_from_memory((const char *)pointer, (unsigned int)length, &parsedPlist, NULL);
     
     if (parsedPlist == nullptr)
     {
--- a/upstream_repo/AltServer/AltServerApp.cpp
+++ b/upstream_repo/AltServer/AltServerApp.cpp
@@ -1333,7 +1333,7 @@
 		auto data = readFile(infoPlistPath.string().c_str());
 
 		plist_t plist = nullptr;
-		plist_from_memory((const char*)data.data(), (int)data.size(), &plist);
+		plist_from_memory((const char*)data.data(), (int)data.size(), &plist, NULL);
 		if (plist == nullptr)
 		{
 			throw InstallError(InstallErrorCode::MissingInfoPlist);
@@ -1370,7 +1370,7 @@
         auto data = readFile(infoPlistPath.string().c_str());
         
         plist_t plist = nullptr;
-        plist_from_memory((const char *)data.data(), (int)data.size(), &plist);
+        plist_from_memory((const char *)data.data(), (int)data.size(), &plist, NULL);
         if (plist == nullptr)
         {
             throw InstallError(InstallErrorCode::MissingInfoPlist);