Update NSPR to 4.12 and NSS to 3.23 on iOS

nss/lib/softoken/sdb.c

Index: nss/lib/softoken/sdb.c
diff --git a/nss/lib/softoken/sdb.c b/nss/lib/softoken/sdb.c
index 16848604c6f11d245104428a8a516d0145714552..36bdcc132f05b4022a6ad3e97aca305ab609db10 100644
--- a/nss/lib/softoken/sdb.c
+++ b/nss/lib/softoken/sdb.c
@@ -235,7 +235,7 @@ sdb_getFallbackTempDir(void)
     const char *zDir = NULL;
 
     azDirs[0] = sqlite3_temp_directory;
-    azDirs[1] = getenv("TMPDIR");
+    azDirs[1] = PR_GetEnvSecure("TMPDIR");
 
     for (i = 0; i < PR_ARRAY_SIZE(azDirs); i++) {
         zDir = azDirs[i];
@@ -1862,7 +1862,7 @@ sdb_init(char *dbname, char *table, sdbDataType type, int *inUpdate,
       * the environment variable is primarily to simplify testing, and to 
       * correct potential corner cases where  */
 
-     env = PR_GetEnv("NSS_SDB_USE_CACHE");
+     env = PR_GetEnvSecure("NSS_SDB_USE_CACHE");
 
      if (env && PORT_Strcasecmp(env,"no") == 0) {
 	enableCache = PR_FALSE;
@@ -2013,7 +2013,7 @@ s_open(const char *directory, const char *certPrefix, const char *keyPrefix,
     accessOps = 1;
     {
         char *env;
-        env = PR_GetEnv("NSS_SDB_USE_CACHE");
+        env = PR_GetEnvSecure("NSS_SDB_USE_CACHE");
         /* If the environment variable is set to yes or no, sdb_init() will
          * ignore the value of accessOps, and we can skip the measuring.*/
         if (!env || ((PORT_Strcasecmp(env, "no") != 0) &&