Update NSPR to 4.12 and NSS to 3.23 on iOS

nss/lib/pk11wrap/pk11util.c

Index: nss/lib/pk11wrap/pk11util.c
diff --git a/nss/lib/pk11wrap/pk11util.c b/nss/lib/pk11wrap/pk11util.c
index 4a384ad5bc2a572675627f2e76dc17766577336f..712f267f114bdedd9f2213a81f39766d22d064ae 100644
--- a/nss/lib/pk11wrap/pk11util.c
+++ b/nss/lib/pk11wrap/pk11util.c
@@ -84,7 +84,7 @@ SECMOD_Shutdown()
     nss_DumpModuleLog();
 
 #ifdef DEBUG
-    if (PR_GetEnv("NSS_STRICT_SHUTDOWN")) {
+    if (PR_GetEnvSecure("NSS_STRICT_SHUTDOWN")) {
 	PORT_Assert(secmod_PrivateModuleCount == 0);
     }
 #endif
@@ -640,6 +640,11 @@ SECMOD_AddNewModuleEx(const char* moduleName, const char* dllPath,
 						PR_TRUE: PR_FALSE;
                         result = PK11_UpdateSlotAttribute(slot, 
 					&(PK11_DefaultArray[i]),  add);
+                        if (result != SECSuccess) {
+                            SECMOD_ReleaseReadLock(moduleLock);
+                            SECMOD_DestroyModule(module);
+                            return result;
+                        }
                     } /* for each mechanism */
                     /* disable each slot if the defaultFlags say so */
                     if (defaultMechanismFlags & PK11_DISABLE_FLAG) {