build: fix configuring when building depends with NO_BDB=1

Currently, if you build depends using `NO_BDB=1` (only sqlite wallets),
./configure will fail as it still tries to find bdb. i.e:
```bash
checking for Berkeley DB C++ headers... default
configure: error: Found Berkeley DB other than 4.8, required for portable BDB wallets (--with-incompatible-bdb to ignore or --without-bdb to disable BDB wallet support)
```

This PR fixes the build such that you can build depends, opting out of
bdb without opting out of wallets entirely, and still configure
successfully.

Author: fanquake

configure.ac

@@ -1326,9 +1326,11 @@ fi
 
 if test x$enable_wallet != xno; then
     dnl Check for libdb_cxx only if wallet enabled
-    BITCOIN_FIND_BDB48
-    if test x$suppress_external_warnings != xno ; then
+    if test "x$use_bdb" != "xno"; then
+      BITCOIN_FIND_BDB48
+      if test x$suppress_external_warnings != xno ; then
         BDB_CPPFLAGS=SUPPRESS_WARNINGS($BDB_CPPFLAGS)
+      fi
     fi
 
     dnl Check for sqlite3

depends/Makefile

@@ -34,6 +34,8 @@ BASE_CACHE ?= $(BASEDIR)/built
 SDK_PATH ?= $(BASEDIR)/SDKs
 NO_QT ?=
 NO_QR ?=
+NO_BDB ?=
+NO_SQLITE ?=
 NO_WALLET ?=
 NO_ZMQ ?=
 NO_UPNP ?=
@@ -233,6 +235,8 @@ $(host_prefix)/share/config.site : config.site.in $(host_prefix)/.stamp_$(final_
             -e 's|@no_qr@|$(NO_QR)|' \
             -e 's|@no_zmq@|$(NO_ZMQ)|' \
             -e 's|@no_wallet@|$(NO_WALLET)|' \
+            -e 's|@no_bdb@|$(NO_BDB)|' \
+            -e 's|@no_sqlite@|$(NO_SQLITE)|' \
             -e 's|@no_upnp@|$(NO_UPNP)|' \
             -e 's|@no_natpmp@|$(NO_NATPMP)|' \
             -e 's|@multiprocess@|$(MULTIPROCESS)|' \

depends/config.site.in

@@ -38,6 +38,14 @@ if test -z "$enable_wallet" && test -n "@no_wallet@"; then
   enable_wallet=no
 fi
 
+if test -z "$with_bdb" && test -n "@no_bdb@"; then
+  with_bdb=no
+fi
+
+if test -z "$with_sqlite" && test -n "@no_sqlite@"; then
+  with_sqlite=no
+fi
+
 if test -z "$enable_multiprocess" && test -n "@multiprocess@"; then
   enable_multiprocess=yes
 fi