feat: enable libcurl for znc-push

Before enabling libcurl in znc-push, some notifications were not
delivered, especially messages that were sent in burst.
Working example:

```
<*push> Building notification to
api.telegram.org/botXXX/sendMessage...
<*push> Request sending
<*push> Status: 200
<*push> Message: OK
...
```

Broken example:

```
<*push> Building notification to
api.telegram.org/botXXX/sendMessage...
<*push> Request sending
...
<Notification not delivered>
```

Ref: https://github.com/amyreese/znc-push/blob/master/README.md#advanced
```
Note: You are strongly encouraged to use libcurl transport. The reason
for that is, that the default CSocket transport doesn't verify server's
SSL certificate which leaves you vulnerable to MITM attacks. However,
use of libcurl will block the main ZNC thread at every push
notification; for installations with many users, libcurl is not yet
ideal, even with the above security concerns in mind.
```

I subsequently enabled libcurl in push.cpp compilation.
I could not modify the Makefile because it is overwritten for every
module downloaded, but I could override the cpp file before building the
module.
After using libcurl, I could receive all the notifications sent by
znc-push.

Author: mbologna

Dockerfile

@@ -17,6 +17,7 @@ RUN \
     boost-dev\
     build-base \
     c-ares-dev \
+    curl-dev \
     cyrus-sasl-dev \
     gettext-dev \
     git \
@@ -55,6 +56,7 @@ RUN \
   tar xf \
     /tmp/znc-push.tar.gz -C \
     /tmp/znc/modules --strip-components=1 && \
+    sed -i '1i #define USE_CURL' /tmp/znc/modules/push.cpp && \
   curl -o \
     /tmp/znc-clientbuffer.tar.gz -L \
     https://github.com/CyberShadow/znc-clientbuffer/archive/master.tar.gz && \

Dockerfile.aarch64

@@ -16,6 +16,7 @@ RUN \
     boost-dev\
     build-base \
     c-ares-dev \
+    curl-dev \
     cyrus-sasl-dev \
     gettext-dev \
     git \
@@ -54,6 +55,7 @@ RUN \
   tar xf \
     /tmp/znc-push.tar.gz -C \
     /tmp/znc/modules --strip-components=1 && \
+    sed -i '1i #define USE_CURL' /tmp/znc/modules/push.cpp && \
   curl -o \
     /tmp/znc-clientbuffer.tar.gz -L \
     https://github.com/CyberShadow/znc-clientbuffer/archive/master.tar.gz && \